On July 22, 2009, in Phuket, Thailand, Secretary of State Hillary Rodham Clinton and representatives from the 10-member Association of Southeast Asian Nations' (ASEAN) signed the Instrument of Extension and the Instrument of Accession to ASEAN's Treaty of Amity and Cooperation (TAC). Secretary Clinton was in Thailand to attend the annual ASEAN Regional Forum Foreign Ministerial. The move came less than six months after she had announced, during a visit to Jakarta, that the Obama Administration would launch its formal interagency process to pursue accession. One of ASEAN's pillars, the TAC was first negotiated in 1976 and subsequently amended to allow non-regional countries to accede. The Administration's move is designed to symbolically boost the United States' standing in Southeast Asia by expanding the multilateral component of U.S. policy in the region. Following consultations with selective offices in the Senate, the Administration decided that accession would take the form of an executive agreement, which does not require Senate approval. The debate over whether the United States should accede to the TAC raised at least three issues for the Obama Administration and the Congress: 1. how would accession to the TAC advance U.S. interests in Southeast Asia? 2. would accession to the TAC constrain U.S. policy in Southeast Asia, particularly with respect to Burma? 3. should the Administration send the TAC to the Senate for ratification? Periodically, Congressional measures have called attention to ASEAN and/or called for upgrading U.S. engagement with ASEAN. In the 109 th Congress, the Senate passed by unanimous consent S. 2697 (Lugar), the United States Ambassador for ASEAN Affairs Act, which mandated the naming of an Ambassador to the organization. None of the congressional measures dealing with U.S. engagement with ASEAN mentioned U.S. accession to the TAC. The Obama Administration's primary motivation for acceding to the TAC appears to have been to send a signal that the United States seeks to upgrade its presence in Southeast Asia. Many leaders in the region have felt neglected by the United States in recent years. ASEAN leaders have long viewed the TAC not only as a constitutional document for the organization, but also as establishing guiding principles that have built confidence among members, thereby contributing to maintaining regional peace and stability. Accession to the TAC by non-members often is seen as a symbol of their commitment to engagement in Southeast Asia and the organization's emphasis on multilateral processes. As shown in Table 1 , prior to July 2009, the United States was the only major Pacific power that had not joined the TAC; traditionally, the U.S. presence in Southeast Asia has been organized primarily along bilateral lines. Additionally, acceding to the TAC is also one of the three requirements for joining the East Asia Summit (EAS), a four-year old forum that features an annual meeting among the heads-of-state of the ASEAN members, China, Japan, South Korea, India, Australia, and New Zealand. The other two requirements are dialogue partnership and significant economic relations with ASEAN, both of which the United States already meets. It is unclear whether the Obama Administration plans to join the EAS, or to what extent U.S. participation would be resisted by EAS members, particularly China and Malaysia, which in the past have voiced reservations with U.S. participation. Australia's accession to the TAC in 2005, which reversed years of official policy, was primarily motivated by Canberra's desire to be a founding member of the EAS. Joining the TAC had been proposed by many in the Asia policy community for several years, and the idea was debated in the George W. Bush Administration. Objections to joining the TAC included arguments that the TAC's emphasis on non-interference in domestic affairs (particularly in Articles 2, 10, and 13) would constrain U.S. freedom of action, particularly its ability to penalize Burma; a concern that the treaty would undermine U.S. security agreements with Asian allies, notably Japan, South Korea, and Australia; a belief that acceding would accord greater legitimacy to the ruling Burmese junta; a view that ASEAN is insufficiently "action-oriented"; and a belief that the TAC is an ineffectual, largely symbolic agreement. Proponents of accession countered that the decisions by U.S. allies Australia, South Korea, and Japan to accede to the TAC should negate concerns that the TAC would constrain U.S. policy and/or undermine U.S. alliances. As discussed in detail below, as part of their accession negotiations, Australia and South Korea both signed side letters with ASEAN that were designed to alleviate similar concerns. (See Appendix B .) Along the same lines, Japan reached an understanding with ASEAN prior to its accession to the TAC. Following the Australian and South Korean model, the Obama Administration negotiated and exchanged side letters with the Chairman of ASEAN (who in July 2009 was the Thai Foreign Minister) designed to prevent the TAC from constraining U.S. foreign policy actions. During the debate over accession, Australia's October 2007 promulgation of targeted financial and travel restrictions on over 400 members of the Burmese regime in the aftermath of the regime's September 2007 crackdown against peaceful protesters was cited as evidence that the TAC would not necessarily constrain U.S. policy. Australia, like Japan, has generally followed a policy of quiet engagement of Burma, seasoned with occasional public criticisms and targeted penalties. Canberra's restrictions against the Burmese regime are not nearly as expansive as U.S. sanctions. During its first weeks in office, the Obama Administration announced it would initiate a review of U.S. policy toward Burma. During her February 2009 visit to Asia, Secretary Clinton said that neither sanctions nor the engagement strategies pursued by ASEAN members were working. One of the world's largest regional groupings, ASEAN is Southeast Asia's primary multilateral organization. Its 10 member-nations include over 500 million people. Geographically, Southeast Asia includes some of the world's most critical sea lanes, including the Straits of Malacca, through which pass a large percentage of the world's trade. The straits also are important routes for U.S. naval deployments around the globe, including the Middle East and South Asia. Southeast Asia has served as a center and a base for terrorist operations by radical Islamist groups, including Al Qaeda, though the threat posed by such indigenous groups appears to have been significantly reduced since the middle of the decade. The region is a key source and transmission point for many of the world's "human security" problems, including smuggling, narcotics trafficking, piracy, human trafficking, and the spread of contagious diseases such as avian influenza. Southeast Asia is home to Indonesia, the world's most populous Muslim nation, which is important to the United States for its size, its democratic example for other majority-Muslim countries, and its status as one of the world's largest carbon emitters, largely by virtue of the rapid pace of deforestation. U.S. relations with Malaysia, another core majority-Muslim ASEAN member, also have global and regional importance because of Malaysia's democratic and economic example (it is a middle income country) and because of its attempts to mediate long-running conflicts between Christian and Muslim factions in the southern Philippines. The region also includes two formal U.S. treaty allies with functioning, although sometimes troubled, democracies—Thailand and the Philippines—as well as another close U.S. security partner, Singapore. Furthermore, diplomatically and strategically, Southeast Asia is the site of a contest for influence among China, the United States, and to a lesser extent Japan. China in particular has expanded its presence and influence in Southeast Asia since the early 2000s. Some commentators have argued that Beijing's increased presence has jeopardized U.S. influence. Others contest this assertion, arguing that the U.S. and China are not locked in a "zero sum" situation in Southeast Asia, that some of China's actions since 2007 have made some Southeast Asians wary of Beijing's actions, and/or that Chinese diplomacy in Southeast Asia is perceived as successful because China has tended to prioritize areas of mutual agreement while putting off issues that are more difficult to resolve. Regardless of whether U.S. interests are materially threatened, China's increased presence in Southeast Asia has made many Southeast Asian leaders eager for a strong U.S. presence in the region. Indeed, one factor motivating the United States' increased engagement with ASEAN in the 2000s has been the desire to support Southeast Asia's political stature as China expands its influence in the region. Collectively, ASEAN is a major U.S. trading partner. Total trade between the United States and the 10 ASEAN countries in 2008 totaled $178 billion. If ASEAN were treated as a single trading partner, it would rank as the fourth largest U.S. export market (at $68.2 billion) and the fifth largest source of U.S. imports (at $110.2 billion) in 2008. Since 2005, between 5%-6% of total U.S. exports by value have been shipped to the ASEAN market, slightly more than exports to Japan. Over the same period, ASEAN has been the source for about 5%-6% of total U.S. imports. ASEAN's share of U.S. trade has fallen since 1995, when it was the destination for nearly 7% of U.S. exports and the source of 8.5% of U.S. imports, by value. Many analysts who see China as a growing power in East Asia point to the surge in its trade with ASEAN countries vis-a-vis that with the United States. Table 2 compares Chinese and U.S. trade with ASEAN for 1995, 2005, and 2008. Over this period, China's trade with ASEAN has expanded sharply in terms of trade volume, percentage increase, and size relative to U.S. trade levels. Table 3 provides trade data on the importance of the United States, as well as of China, from ASEAN's perspective (i.e., using ASEAN trade data). These data indicate that: From 1995 to 2007, the share of ASEAN's imports that came from China increased from 2.2% to 12.7%, while the share that came from the United States dropped from 14.6% to 9.6%. From 1995 to 2008, the share of ASEAN exports that went to China rose from 2.1% to 9.7%, while the share of ASEAN's exports that went to the United States fell from 18.5% to 11.5%. According to ASEAN official data, in 2008 (the latest year in which comprehensive ASEAN trade data are available), its top trading partners (excluding intra-ASEAN trade) were Japan (11.4% of total), the European Union (11.8%), China (11.3%), and the United States (10.6%). The United States was ASEAN's third largest export market and its fourth largest source of imports, while China was ASEAN's fourth largest export market and its largest source of imports. The United States is a bigger source of ASEAN's foreign direct investment (FDI) than China (although the European Union and Japan are the two largest investors). During 2006-2008, cumulative U.S. FDI flows to ASEAN were $12.8 billion (or 8.2% of the total), making the United States ASEAN's third largest source of FDI (excluding FDI flows from other ASEAN countries). Over this period, China's FDI flows to ASEAN totaled $3.5 billion or 1.9% of the total, making China the ninth largest source of ASEAN's FDI. In 2008, U.S. FDI flows to ASEAN totaled $3.0 billion versus $619 million from China. (See Table 4 .) Established in 1967 with five original members, ASEAN has evolved from its original Cold War-era goal of containing Chinese and Vietnamese communism. Increasingly, ASEAN is a vehicle for Southeast Asian nations to resolve problems through the "ASEAN way" of informal, consensus-based, and confidence-building efforts rather than through binding commitments or agreements. Since the early 1990s, ASEAN also has been playing a leading role in moving the countries of East Asia toward organizing into cooperative multilateral arrangements. ASEAN often takes the lead in building multilateral institutions because it is viewed as less threatening than China or Japan. Some analysts speculate that this role of neutral convener may be losing some of its utility, as evidenced by the first-ever standalone China-Japan-South Korea tripartite summit in December 2008. Follow-on summits are expected. Previously, the leaders of the three countries had met only on the sidelines of the annual ASEAN "Plus Three" gathering. ASEAN's consensus-based decision-making and policy of non-interference in members' affairs have led some commentators, particularly from outside the region, to dismiss the organization as a mere "talk shop." They cite ASEAN's ineffectiveness in dealing with transnational issues like drug trafficking, human trafficking, wildlife trafficking, and illegal logging. ASEAN also has not appeared to play a role in some conflicts among members, such as the 2008 and 2009 border skirmishes between Thailand and Cambodia. Indeed, frustrations with ASEAN's internal procedures, continued difficulties with Burma, and the expansion of non-ASEAN regional groupings in Asia have led some prominent Southeast Asians to publicly call attention to ASEAN's limitations. However, many Southeast Asians contend that ASEAN has been critical to fostering stability, reducing conflict, and promoting trade and economic growth. In the 2000s, some ASEAN members—particularly Indonesia and the Philippines—have pushed to expand the organization's powers. These moves often have been resisted by other members, particularly Vietnam, Cambodia, and Burma. For instance, in 2008, ASEAN adopted a new charter, early drafts of which included provisions for sanctions and a system of compliance monitoring for ASEAN agreements. However, these items eventually were stripped from the charter. In July 2009, ASEAN's Foreign Ministers approved the creation of the organization's first-ever human rights body. The ASEAN Intergovernmental Commission on Human Rights is designed to focus on promoting human rights. The body, launched in October 2009, will not have the power to penalize human rights violations and/or violators. The TAC establishes general principles governing the relations between State parties, with the intention of promoting "perpetual peace, everlasting amity and cooperation" within Southeast Asia. Towards this end, it provides a mechanism for the pacific settlement of regional disputes between TAC parties. As drafted in 1976, the TAC was open to ratification by the five original members of ASEAN, and was only open to accession by other Southeast Asian States. The TAC was subsequently amended in 1987 to permit the accession of States outside Southeast Asia with the consent of the five ASEAN members, and to establish rules concerning when States outside Southeast Asia could participate in the agreement's dispute-settling mechanism. The TAC was further amended in 1998 to reflect the expansion of ASEAN to 10 members, and to make accession to the TAC by any additional States outside Southeast Asia contingent upon the approval of all 10 ASEAN members. Article 1 of the TAC announces that the purpose of the agreement is to promote peace and cooperation among the parties. Article 2 provides that in their relations with one another, parties shall be guided by six principles: Mutual respect for the independence, sovereignty, equality, territorial integrity, and national identity of all nations; The right of every State to lead its national existence free from external interference, subversion, or coercion; Non-interference in the internal affairs of one another; Settlement of differences or disputes by peaceful means; Renunciation of the threat or use of force; and Effective cooperation among themselves. While TAC Article 2 describes these principles as "fundamental," it does not specify that they are the sole principles that may inform relations between parties. TAC Article 3 obliges parties to endeavor to develop and strengthen their mutual relations and fulfill their obligations under the agreement in good faith. TAC Articles 4-9 outline party obligations concerning mutual cooperation. Articles 4 and 5 provide that parties shall promote and strengthen active cooperation in the economic, social, technical, scientific and administrative fields on the basis of equality, non-discrimination and mutual benefit. Articles 6 and 7 provide that parties shall collaborate (including through the use of international and regional organizations outside Southeast Asia) to accelerate the region's economic growth, including through promotion of greater use of parties' agriculture and industries, the expansion of trade, and the improvement of economic infrastructure. Article 8 states that parties shall strive to achieve cooperation in the form of training and research facilities in the social, cultural, technical, scientific and administrative fields. Article 9 provides that parties shall retain regular contacts with one another on international and regional matters with a view towards coordinating their policies. TAC Article 10 provides that no party shall "in any manner or form participate in any activity which shall constitute a threat to the political and economic stability, sovereignty, or territorial integrity of another High Contracting Party." The agreement does not elaborate on the types of activity constituting a "threat" to the political or economic stability, sovereignty, or territorial integrity of another party, or what type of conduct is intended to be barred by the agreement's prohibition on "participat[ion] in any activity" constituting a threat to another party. Presumably, prohibited activity would have to be of a particularly severe nature to constitute a threat to the stability, sovereignty, or integrity of another TAC party. TAC Articles 11 and 12 provide that parties shall endeavor to promote national and regional resilience. TAC Articles 13-17 concern the pacific settlement of disputes between parties. Article 13 states that parties shall act in good faith to prevent disputes from arising between them. Parties are obliged to "refrain from the threat or use of force," and are instead called upon to settle disputes "through friendly negotiations." Towards that end, Article 14 establishes a High Council, composed of a ministerial level representative of each State party, to resolve disputes. As amended by the 1987 Protocol, the dispute settlement system established by Article 14 is only applicable to State parties outside Southeast Asia when those States are "directly involved in the dispute to be settled." TAC Article 15 states that in cases where disputes cannot be settled via direct negotiation between TAC parties, the High Council shall take cognizance of the matter and recommend an appropriate means of settlement, such as good offices, mediation, inquiry, or conciliation. The High Council may also, with the consent of the parties to the dispute, act as a committee for mediation, inquiry, or conciliation. When necessary, the Council shall also recommend appropriate measures to prevent further deterioration of the situation. TAC parties are not legally compelled to abide by the High Council's recommendations. TAC Article 16 limits application of Article 15 to instances where all parties to the dispute agree to its application. Perhaps for this reason, the High Council has never been convened to resolve a dispute arising under TAC. TAC Article 17 states that nothing in the agreement precludes parties from seeking recourse pursuant to the modes of peaceful settlement contained in Article 33(1) of the U.N. Charter. Article 33(1) of the Charter provides that U.N. Member States that are parties to a dispute threatening international peace and security shall "seek a solution by negotiation, enquiry, mediation, conciliation, arbitration, judicial settlement, [and may] resort to regional agencies or arrangements, or other peaceful means of their own choice." TAC Article 17 also states that parties are encouraged to resolve disputes through friendly negotiations "before resorting to the other procedures provided for in the Charter of the United Nations." This language appears intended to ensure that TAC's dispute-resolution requirements are not interpreted as violating Article 103 of the U.N. Charter, which provides that Member States' obligations under the U.N. Charter override any conflicting obligations under other international agreements. TAC Articles 18-20 relate to treaty ratification and accession, entry into force, and the authoritative text of the agreement. As amended by the 1987 and 1998 Protocols, Article 18 provides that accession of any State outside Southeast Asia is subject to the consent of all the States in Southeast Asia, which the agreement expressly lists as the 10 current members of ASEAN. Article 19 describes the procedure by which TAC entered into force. Article 20 notes that the treaty is drawn in the equally authoritative language of all contracting parties. A common English text has also been agreed upon, with any divergent interpretation of the common text to be settled by negotiation. The TAC does not contain provisions concerning withdrawal from the agreement by a State party, the agreement's relationship to other multilateral or bilateral agreements to which TAC parties may belong, or the remedies available to a party in the event that its rights under the agreement are violated by another party and neither direct negotiation by the parties nor the assistance from the High Council resolves the violation. These matters would presumably be handled in accordance with customary practice, absent evidence of a contrary understanding by TAC parties. TAC Article 18, as amended, requires the consent of all ASEAN members before candidate States may accede to the agreement. Formal exchanges of correspondence and consultation between ASEAN members and candidates for accession to the TAC are generally made between the candidate and the ASEAN Chairman. In some instances, a candidate will sign a declaration signifying its intent to accede to the TAC contingent upon completion of any necessary domestic procedures. If all ASEAN Members consent to a candidate's proposed accession to the TAC, the Chairman is authorized to sign a preliminary declaration of consent to accession on behalf of ASEAN Members. The accession process is completed once all ASEAN foreign ministers sign an instrument formally consenting to the candidate party's accession to the TAC, and the candidate party signs and submits the instrument of accession. The instrument of accession is typically signed and deposited by the acceding State's foreign minister. Negotiations regarding accession to the TAC may raise issues related to the interpretation and application of the agreement's provisions. In many cases, a party will attach a reservation, declaration, or understanding to an agreement at the time of accession or ratification when questions or concerns arise regarding an agreement's potential application. The TAC does not contain a provision barring this practice. However, ASEAN members have historically been unwilling to permit an acceding State to make a reservation or declaration upon accession. Some States seeking to accede to the TAC have instead sought to reach common understandings with ASEAN members regarding the interpretation of certain TAC provisions, and have recorded these shared understandings in an exchange of notes ("side letters") with the ASEAN Chairman prior to acceding to the TAC. Although these side letters are not understood to amend or modify the TAC, they may serve as important interpretative guidance as to the meaning of its provisions. The Vienna Convention on the Law of Treaties, which is recognized as an authoritative guide to treaty law and practice, states that "any instrument which was made by one or more parties in connection with the conclusion of the treaty and accepted by the other parties as an instrument related to the treaty" may be relied upon to assist in interpreting the underlying treaty. The United States memorialized its understanding of certain TAC requirements during communications with the ASEAN Chairman regarding its proposed accession. This side letter is attached as Appendix A . Similar communications appear to have been made by Australia, South Korea, Japan, and New Zealand when they acceded to the TAC. Most of these communications have not been made publicly available. However, the side letters memorializing understandings reached by Australia with ASEAN members during the TAC accession process are attached as Appendix B . One of the most notable issues that U.S. policymakers were required to consider when contemplating whether to join the TAC was the form that U.S. accession should take. Legally binding international agreements entered into by the United States take the form of either a treaty or an executive agreement. If an agreement is entered into as a treaty, the Senate must provide its advice and consent by a two-thirds majority for the agreement to become "the Law of the Land." The great majority of international agreements that the United States enters into are not treaties but executive agreements—agreements made by the executive branch that are not submitted to the Senate for its advice and consent. Depending upon the circumstances, authority to enter an executive agreement may derive from different sources, including from a statute enacted by Congress which authorizes the Executive to enter the agreement (a congressional-executive agreement), or pursuant to the Executive's constitutional authority in a given area (sole executive agreement). There are a number of provisions in the Constitution that may confer limited authority upon the President to promulgate sole executive agreements, including his Commander-in-Chief authority and power in the area of foreign affairs. Ultimately, the executive branch opted to accede to the TAC as a sole executive agreement, presumably because the agreement is deemed to focus solely upon relations between TAC parties and impose no requirements upon parties' domestic activities. Arguably, U.S. accession to the TAC could have taken the form of a treaty, with accession being subject to the advice and consent of the Senate, or an executive agreement. Agreements concerning friendly relations, consultation, and cooperation between countries have taken both forms. The United States has concluded numerous agreements which concern amity or friendly relations between parties as treaties. However, these agreements have traditionally focused on different matters than the TAC. Agreements concerning amity and cooperation that have taken the form of treaties generally focus on the rights afforded to each party's nationals in the territory of the other State party. In contrast, the ASEAN TAC appears to focus exclusively on State-to-State relations. It does not appear that the TAC is intended to afford parties' nationals with individually enforceable rights in the territory of other TAC parties, or otherwise modify a State's internal practices. The United States has concluded several international agreements as executive agreements that address one or more issues covered by the ASEAN TAC—e.g., cooperation on matters involving security, economics, and science and technology. In a few instances, the United States has entered international agreements of similar breadth to the TAC (and in some cases greater breadth) by way of executive agreement. For example, in 1982, the United States concluded an executive agreement with Spain in order to "promote their cooperation in the common defense, as well as … economic, scientific, and cultural cooperation." Beyond establishing a general framework for relations in these areas, the agreement also contained specific provisions related to basing rights, defense procurement, the status of U.S. forces in Spain, and the establishment of joint committees to promote cooperation on economic, scientific, and cultural matters. The form that U.S. accession to the TAC would take was the subject of discussion between the executive and legislative branches. One issue that was discussed was the significance of the agreement being titled the Treaty of Amity and Cooperation. Although agreements similar to the TAC have often been entered via executive agreements, none of these agreements referred to themselves as "treaties." An examination of official compendiums of international agreements and other sources by CRS found only a single agreement currently in force at the time of U.S. accession to the TAC which, although referring to itself as a "treaty," was concluded by the United States via executive agreement —the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure. Although the TAC refers to itself as a "treaty," it is important to distinguish the meaning of this term in the context of international law, in which "treaty" and "international agreement" are synonymous terms for all binding agreements, and "treaty" in the context of domestic American law, in which the term more narrowly refers to a particular subcategory of binding international agreements. In other words, the fact that the TAC uses the word "treaty" in its title does not necessarily mean that it must take the form of a "treaty" for purposes of U.S. law. Perhaps to prevent confusion, U.S. negotiators have generally avoided using the term "treaty" whenever drafting language of an international agreement which is unlikely to be presented to the Senate for its advice and consent. Because the United States did not participate in the drafting of the TAC, it was not involved in the decision to entitle it a "treaty." Shortly after the United States acceded to the TAC by way of executive agreement, Senator Mitch McConnell submitted into the Congressional Record a July 10, 2009, letter to Secretary of State Hillary Clinton that had been signed by Senator McConnell as well as Senators John Kerry and Richard Lugar, the Chairman and Ranking Member of the Senate Foreign Relations Committee, respectively. In the letter, written prior to U.S. accession to the TAC, the Senators expressed their view that "it is consistent with U.S. practice for the United States to accede to the TAC as an executive agreement." However, the Senators also expressed their belief that, while the TAC could properly be entered as a sole executive agreement, other agreements labeled "treaties" should generally be submitted to the Senate for its advice and consent. Specifically, the letter stated: We note that the title of the agreement refers to the agreement as a "treaty," and we are unaware of any precedent for the United States acceding to an agreement styled as a "treaty" without the advice and consent of the Senate as provided for in Article II, Section 2 of the Constitution. At the same time, we are mindful that other factors apart from the formal name of the agreement could suggest that it is consistent with U.S. practice for the United States to accede to the TAC as an executive agreement. Of particular importance, the agreement is largely limited to general pledges of diplomatic cooperation and would [generally] not appear to obligate the United States to take (or refrain from taking) any specific action … We also note that the United States did not take part in the negotiations among ASEAN countries leading up to the conclusion of the TAC in 1976, or in the decision to characterize it as a treaty. In light of these unique considerations, we will not object to the Department's plan to accede to the TAC as an executive agreement. We continue to believe, however, that the use of the term "treaty" in the title of an agreement will generally dictate that Senate advice and consent will be required before the United States may accede to the agreement. In this regard, treatment of the TAC as an executive agreement should not be considered a precedent for treating future agreements entitled "treaties" as sole executive agreements. To ensure our understanding that the process surrounding this agreement is not misinterpreted in the future as a precedent, we will submit this letter into the Congressional Record. We would also request that the State Department include it in the next edition of the Digest of United States Practice in International Law. If Congress believes that accession to the TAC via sole executive agreement is inappropriate, or disagrees with the manner in which the Executive implements TAC requirements, it has several tools available by which it may address these concerns. For example, Congress could enact new legislation that modifies or repudiates U.S. adherence to or implementation of the agreement. It could require the Executive to submit information to Congress or congressional committees regarding U.S. implementation of its TAC commitments. Congress could also limit or prohibit appropriations necessary for the Executive to implement the provisions of the TAC, or condition such appropriations upon the Executive implementing the agreement in a particular manner. While the TAC may impose obligations upon parties in their mutual relations as a matter of international law , its requirements do not appear to be of the kind that would create binding federal law enforceable by U.S. courts. Many of the agreement's clauses address parties' obligations in non-specific terms—e.g., requiring parties to "endeavor to develop and strengthen … ties" and "achieve the closest cooperation on the widest scale." Such clauses appear to lack the precision necessary to be considered legally enforceable, though they may nonetheless carry political or moral weight for TAC parties. More broadly, while the agreement establishes guidelines for parties in their relations with one another, it does not expressly require parties to modify any of their existing domestic laws, even if such laws arguably conflict with the principles espoused by the TAC. Instead, the TAC expressly calls on parties to resolve any dispute between them through diplomatic means. Accordingly, it does not appear that U.S. accession to TAC would have the effect of modifying or limiting the enforcement of existing domestic laws, though the United States would have an obligation under customary international law to execute its obligations under the TAC in good faith. Nonetheless, the TAC may have implications for U.S. policies, at least as a matter of international law. Some States that have acceded to the TAC, including the United States, negotiated side letters that address the issues discussed in the following sections. TAC Article 2 provides that a "fundamental" guiding principle in the relationship between parties is the "renunciation of the threat or use of force." This prohibition is similar to that contained in Article 2(4) of the U.N. Charter, which bars U.N. Member States "from the threat or use of force against the territorial integrity or political independence of any state." Unlike the U.N. Charter, however, the TAC does not provide an express exception to this bar in cases where force is used in self-defense. Even in the absence of a TAC provision recognizing parties' right to use force in self-defense, there is good reason to believe that the agreement is not intended to abrogate this right. Although TAC Article 2 lists six fundamental guiding principles in relations between TAC parties, including renunciation of the threat or use of force, it does not specify that these are the sole principles that may guide relations between State parties. Article 51 of the U.N. Charter recognizes that Members possess "the inherent right of individual or collective self-defense if an armed attack occurs." A nation's right to defend itself from attack is believed by many to be a peremptory norm ( jus cogens ), and accordingly any provision of an international agreement that derogated from this principle would not be legally binding. As such, it seems reasonable to interpret the TAC in a manner that would not be inconsistent with well-established principles concerning a nation's right to defend itself. Nonetheless, in negotiations concerning accession to the TAC, some States have found it necessary to exchange side letters in which it was made clear that parties to the TAC did not interpret the agreement as modifying parties' rights and obligations under the U.N. Charter, including as they relate to the right to self-defense. Related considerations might be raised with respect to the TAC's effect upon U.S. security arrangements. The United States is a party to numerous bilateral and multilateral security arrangements, including some which oblige parties to assist in the defense of any party that is attacked. Some TAC parties with security arrangements with the United States acceded to the TAC after reaching an understanding with ASEAN members that the TAC was not intended to affect other agreements to which they were parties. Prior to acceding to the TAC, the United States exchanged side letters reflecting its understanding that nothing in the TAC would affect its existing bilateral or multilateral relationships, its rights and obligations under the U.N. Charter, or its ability to take actions it "considers necessary to address a threat to its national interests." The TAC might also be interpreted as having implications for U.S. policy on matters occurring in the territory of another party to the agreement, if the policy is interpreted as violating the TAC parties' obligations concerning non-interference. TAC Article 2 provides that relations between parties shall be guided by the principle of "non-interference in the internal affairs of one another." This obligation could be interpreted as being a narrowly circumscribed requirement, prohibiting parties from actively attempting to undermine other parties' sovereignty or territorial integrity. However, it is possible that some countries might argue that the prohibition is more broadly applicable to TAC party activities towards one another, including, for example, criticism of another party's domestic human rights record. It is also possible that some countries may argue that the TAC bars the imposition of economic or other sanctions upon a TAC party on account of that party's domestic activities. This issue may be of particular concern for the United States on account of its stringent economic sanctions regime against Burma, a member of ASEAN whose consent is necessary for U.S. accession. State practice arguably conflicts with the view that the TAC is intended to deter parties from commenting upon or engaging on matters of international interest that arise within the territory of another TAC party. Indeed, some TAC parties have adopted specific measures, including economic sanctions, to deter human rights violations and other practices occurring in the territory of another party. For example, as mentioned above, both Australia and France, which are each parties to the TAC, have imposed sanctions upon Burma. Nonetheless, it is possible that U.S. sanctions policy may become an issue of contention with some TAC members. The United States and most other parties to the TAC are also parties to international agreements that obligate or permit members to take action to deter specified activities arising in other countries, including with regard to matters involving unfair trade practices, transnational criminal activity, international terrorism, and gross human rights violations. Further, all TAC parties are members of the United Nations, and may be required to comply with Security Council resolutions imposing economic sanctions upon a particular country (including, potentially, another party to TAC). In addition, Article 1 of the U.N. Charter provides that one of the purposes of the organization is "to achieve international cooperation ... in promoting and encouraging respect for human rights and for fundamental freedoms for all without distinction as to race, sex, language, or religion." This language arguably imposes a right and obligation upon U.N. Members to abide by these principles in their relations with other States. Some States acceding to TAC have exchanged side letters with ASEAN Members to clarify the parties' mutual understanding that the TAC is not intended to prevent parties from exercising rights and obligations under other international agreements, including the U.N. Charter. Side letters exchanged by the United States prior to its accession to the TAC also reflect this understanding regarding the TAC's relationship with other agreements. Although the TAC was "originally conceived as a legally-binding code of inter-State conduct among Southeast Asian countries," it was subsequently amended to permit the accession of States located outside Southeast Asia. Since that time, several non-Southeast Asian States have acceded to the TAC (see Table 1 ). While some provisions of the TAC clearly focus on parties' obligations with respect to the region of Southeast Asia, other provisions of the agreement could be interpreted as being applicable to relations between parties outside the region as well. In acceding to the TAC, some States outside Southeast Asia, including the United States, exchanged side letters to clarify their mutual understanding with ASEAN Members that the agreement was not intended to govern relations between TAC parties outside Southeast Asia, but only TAC parties' relations with Southeast Asian States. As previously discussed, when the TAC was amended to permit accession by States outside Southeast Asia, it limited their participation in the High Council to instances where the State was directly involved in the dispute to be settled. In contrast, Southeast Asian States are permitted to participate in all High Council meetings, regardless of whether they are parties to the dispute to be settled. The purpose of this limitation appears to have been to ensure that the focus of the TAC remained on Southeast Asia. In acceding to the TAC, Australia exchanged side letters with ASEAN members clarifying each side's understanding of the rights of States outside Southeast Asia pursuant to TAC Articles 14 and 16. The letters reflected the shared understanding that the High Council could not resolve a dispute in which a State outside Southeast Asia was directly involved without the State's consent, and that if the State agreed to the High Council being convened, it would be permitted to participate in the Council. The United States did not include a similar clarification in its side letter with the ASEAN Chairman. Appendix A. Side Letter from United States to ASEAN Concerning U.S Accession to the TAC and Mutual Understandings Concerning the Agreement Appendix B. Side Letters Between Australia and ASEAN Concerning Australia's Accession to the TAC and Mutual Understandings Concerning the Agreement H.E. Mr Somsavat Lengsavad Deputy Prime Minister and Minister of Foreign Affairs Lao People's Democratic Republic Your Excellency I have the honour to inform Your Excellency that Australia has decided to accede to the Treaty of Amity and Cooperation in South East Asia (the Treaty), in accordance with Article 18. The Australian Government is pleased to note that Australia's accession to the Treaty will provide further confirmation of the strong friendship, close ties and extensive common interests and objectives which Australia shares with ASEAN Member countries, both individually and collectively. The Australian Government's decision to accede to the Treaty has been greatly assisted by the extensive discussions which Australian officials have had with ASEAN counterparts on the Treaty. In that context, the Australian Government, in taking the decision to accede to the Treaty, is pleased to note the following understandings of key provisions of the Treaty, on a non-prejudice basis to ASEAN. First, Australia's accession to the Treaty would not affect Australia's obligations under other bilateral or multilateral agreements. Second, the Treaty is to be interpreted in conformity with the United Nations Charter, and Australia's accession would not affect Australia's rights and obligations arising from the Charter of the United Nations. Further, the Treaty will not apply to, nor affect, Australia's relationships with states outside South-East Asia. Finally, Articles 14 and 16 of the Treaty effectively provide that, when a state outside South-East Asia to the Treaty is directly involved in a dispute, the agreement of that state-party is required before the High Council can be convened. Should the High Council be convened, that state would be entitled to participate in the High Council. The Australian Government is pleased to note that it will lodge a formal instrument of accession to the Treaty following completion of Australia's domestic treaty process, including the necessary consultation with Parliament. I thank you for your assistance with this matter, and look forward to receiving your reply. Yours sincerely SIGNED Alexander Downer LAO PEOPLE'S DEMOCRATIC REPUBLIC Peace, Independence, Democracy, Unity, Prosperity Deputy Prime Minister, Minister for Foreign Affairs ___________ Vientiane, 23 July 2005 Excellency, I would like to express my thanks for Your Excellency's letter dated 13 July 2005 addressed to me as Chairman of the 38 th ASEAN Standing Committee, concerning the intention of Australia to accede to the Treaty of Amity and Cooperation in Southeast Asia. We believe that Australia's accession to the Treaty of Amity and Cooperation in Southeast Asia would further contribute to the strengthening of cooperation between ASEAN and Australia, particularly in the promotion of peace, security and cooperation in the region. I look forward to receiving Australia's formal instrument of accession to the Treaty. To: His Excellency Alexander Downer MP Minister of Foreign Affairs Parliament House Canberra ACT 2600 AUSTRALIA CC: - All ASEAN Foreign Ministers - Secretary-General of ASEAN

Summary: On July 22, 2009, during Secretary of State Hillary Rodham Clinton's visit to Southeast Asia, the United States acceded to the Association of Southeast Asian Nations' (ASEAN) Treaty of Amity and Cooperation (TAC), one of the 10-nation organization's core documents, as had been amended by the 1987 and 1998 TAC Protocols. The move came less than six months after Secretary of State Clinton announced in Jakarta that the Obama Administration would launch its formal interagency process to pursue accession. This report analyzes the legal and diplomatic issues involved with accession to the TAC. ASEAN is Southeast Asia's primary multilateral organization. Its 10 member-nations include over 500 million people. Collectively, ASEAN is one of the United States' largest trading partners, constituting about 5%-6% of total U.S. trade. Geographically, Southeast Asia includes some of the world's most critical sea lanes, including the Straits of Malacca, through which pass a large percentage of the world's trade. The TAC was first negotiated in 1976 and subsequently amended to allow non-regional countries to accede. Fifteen countries have done so, including U.S. allies Japan, South Korea, and Australia, as well as China, Russia, and India. Within ASEAN, accession to the TAC by non-members often is seen as a symbol of commitment to engagement in Southeast Asia, and to the organization's emphasis on multilateral processes. The United States is the last major Pacific power to have acceded. The fact that the United States was not a party to the TAC had been one of many pieces of evidence that Southeast Asian leaders cited in arguing that the United States neglected Southeast Asia generally, and ASEAN specifically. Southeast Asian leaders generally have welcomed the Obama Administration's move, which seems to be designed to boost the United States' standing in Southeast Asia by expanding the multilateral component of U.S. policy in the region. Some U.S. and Southeast Asian officials and analysts say that expanding U.S. engagement with ASEAN will help boost Southeast Asia's political stature, particularly as China seeks to continue expanding its influence in the region. The major concern with accession is whether the TAC's emphasis on non-interference in other countries' domestic affairs will constrain U.S. freedom of action, particularly its ability to maintain or expand sanctions on Burma. Proponents of accession often note that Australia has imposed and expanded financial and travel restrictions on Burma since it acceded in 2005. Canberra's restrictions are far less extensive than the sanctions the United States maintains on Burma. The Administration and ASEAN negotiated and exchanged side letters designed to alleviate these concerns. Other objections to accession included arguments that it will accord greater legitimacy to the ruling Burmese junta; a view that ASEAN is insufficiently "action-oriented"; and a belief that the TAC is an untested, arguably ineffectual agreement. One issue for U.S. policymakers was whether accession to the TAC should take the form of a treaty, subject to the advice and consent of the Senate, or whether the President already has sufficient authority to enter the TAC without further legislative action being necessary. Ultimately, after consulting with selective offices in the Senate, the Administration decided that accession would take the form of an executive agreement, which does not require Senate approval.