The North Atlantic Treaty Organization (NATO) has been the cornerstone for transatlantic security and defense cooperation since its founding in 1949. As NATO continues to evolve to confront emerging regional and global security challenges, the 112 th Congress could play an important role in determining the future direction of the alliance and U.S. policy toward it. This includes addressing key issues that are expected to be discussed at NATO's upcoming summit in Chicago. Issues of importance to Congress could include ongoing NATO operations in Afghanistan, off the Horn of Africa, and in the Balkans; the development of allied military capabilities and a NATO territorial missile defense system; NATO's nuclear force posture; NATO's relations with non-NATO members; and implementation of NATO's 2010 Strategic Concept. Since the last NATO summit in Lisbon, Portugal, in November 2010, the alliance has recorded some important achievements and faced considerable challenges in pursuit of its agreed strategic goals. In Lisbon, the allies adopted a new Strategic Concept in an effort to clarify NATO's role in the 21 st century security environment. The new NATO blueprint outlined three core tasks: collective defense; crisis management; and cooperative security. On the issue of collective defense, the allies have committed to maintaining an appropriate mix of nuclear and conventional forces to defend alliance territory and to developing a ballistic missile defense capability based largely on the U.S. European Phased Adaptive Approach (EPAA, discussed in more detail below). Some issues remain divisive, however. For example, some allies continue to question the utility of U.S. non-strategic nuclear weapons deployed in Europe, while others have argued that a continued focus on large-scale "out-of-area" operations and unconventional security threats could compromise the alliance's ability to defend the territory of NATO member states. With respect to crisis management, ongoing operations in Afghanistan and the Balkans as well as the alliance's 2011 operation in Libya demonstrated NATO's capacity to respond simultaneously to multiple security crises. At the same time, each of the missions also exposed significant shortfalls in allied military capabilities. Calls from some allies for an accelerated transition away from combat operations in Afghanistan and the fact that no more than 14 of 28 allies participated in the Libya operation have also prompted many observers to question alliance solidarity and to express doubts about the appetite for future "out-of-area" operations, particularly on the scale of the Afghan mission. On the issue of cooperative security, NATO has sought to enhance its relations with non-NATO member states and other multilateral institutions to allow for stronger regional political and military cooperation and increased partner participation in alliance operations. However, NATO's relations with some key partners, including Russia, continue to be marked by disagreement and deadlock. The global economic downturn and ongoing European debt crisis and the budgetary constraints facing many allied governments on both sides of the Atlantic may pose one of the biggest challenges to alliance capabilities and solidarity. Most European allies have enacted far-reaching budget cuts, including to what had already been declining national defense budgets in most cases. Some observers worry that alliance members will be unable or unwilling to contribute and develop the military capabilities necessary to meet allied security objectives and that this, in turn, could lead to a diminished ability to meet NATO's collective security goals. Others argue that current fiscal constraints only heighten the importance of pooling scarcer resources at the alliance level and cooperating to realize common defense and security objectives. In any case, most observers agree that the current transatlantic burden-sharing situation, with the United States accounting for over two-thirds of alliance defense spending, could be unsustainable. Far-reaching defense budget cuts in the United States and the planned withdrawal of two of the U.S. Army's four Brigade Combat Teams based in Europe have also raised questions within the alliance about future U.S. commitments to European security. NATO's 2012 summit of alliance heads of state and government is scheduled to take place in Chicago on May 20-21. U.S. and NATO officials have outlined what they expect to be the Summit's three main agenda items: Defining the next phase of formal transition in Afghanistan and shaping a longer term NATO commitment to the country after the planned end of combat operations by the end of 2014; Securing commitments to maintain and develop the military capabilities necessary to meet NATO's defense and security goals, including through a new "Smart Defense" initiative; and Enhancing NATO's partnerships with non-NATO member states. The allies also plan to consider the results of an ongoing Deterrence and Defense Posture Review (DDPR), for which they called at the Lisbon Summit. Although NATO is not expected to issue membership invitations to any of the four countries currently seeking NATO membership, they could reaffirm their commitment to do so in the future. In Chicago, alliance leaders are expected to further develop plans for the transition of full responsibility for security to Afghans by the end of 2014 and to define NATO's role in the country after the changeover. The transition would mark the end of what has been the largest and longest combat operation in NATO's history. According to NATO Secretary General Anders Fogh Rasmussen, 22 non-NATO partners that have an interest in stabilizing Afghanistan will attend the Summit. Some analysts point out, however, that the possible absence of Pakistan—one of the region's most influential actors—from the Summit could be emblematic of the significant challenges NATO faces as it seeks to secure the cooperation of Afghanistan's neighbors in its evolving strategy. U.S. and NATO officials outline the following three Afghanistan-related priorities for Chicago: Identifying milestones in 2013 for NATO's transition from a primary emphasis on combat to a primary emphasis on support—in particular, training, advising, and assisting Afghan forces and authorities; Defining the appropriate size of the Afghan National Security Forces (ANSF) after 2014 and securing commitments from NATO member states to help fund and sustain the ANSF after the withdrawal of allied combat forces; and Refining the terms of a NATO-Afghanistan relationship after 2014. Statements by several alliance leaders earlier this year, including newly elected French President François Hollande and U.S. Secretary of Defense Leon Panetta, had led some observers to speculate that some allies could call for an accelerated withdrawal out of Afghanistan at the Chicago Summit. NATO officials say that a further withdrawal of forces in 2013 is in line with existing transition plans. At the same time, they highlight the importance of maintaining some level of combat forces in Afghanistan throughout 2014, even after Afghan forces have taken lead responsibility for security across the country. On May 13, 2012, Afghan President Hamid Karzai announced the beginning of the third "Tranche" of the formal transition process in Afghanistan. According to U.S. officials, Afghan forces now have lead security responsibility over half of the Afghan population. Upon completion of "Tranche 3" of the transition—which reportedly could come within six months—Afghan authorities will have lead security responsibility for 75% of the population. Between now and the end of 2014, NATO forces increasingly are to increasingly take a supporting role, focusing on training and assisting Afghan forces. The Obama Administration reportedly has been leading efforts to raise funds to sustain the ANSF beyond 2014. According to press reports, NATO and the United States estimate that maintaining the ANSF at adequate levels beyond 2014 would cost approximately $4.1 billion annually. In testimony to the Senate Foreign Relations Committee on May 10, 2012, Assistant Secretary of State Philip Gordon said that the United States is seeking a collective annual commitment of about $1.3 billion from its allies and expects the Afghan government to contribute about $500 million annually. U.S. officials reportedly have said the United States could cover the additional cost. Other allies reportedly have been reluctant thus far to make specific commitments ahead of the Summit. Observers expect such support would be necessary for at least 10 years after 2014, reflecting President Karzai's request for international support during a 10-year "transformation" period. Plans for NATO's involvement in Afghanistan after 2014 remain unclear, though some NATO member states—including the United States, United Kingdom (UK), France, and Italy—have signed bilateral agreements with the Afghan government that outline broad commitments after the NATO draw-down. Most member state governments face considerable public opposition to a significant continued combat role in Afghanistan. As of April 18, 2012 there were 128,961 troops from 50 countries serving in NATO's International Security Assistance Force (ISAF) in Afghanistan, with the 28 NATO members providing the core of the force. The largest ISAF troop deployments come from the United States (90,000), the UK (9,500), Germany (4,900), Italy (3,816), France (3,308), and Poland (2,457). Europe's current financial problems have led to heightened concern about European allies' willingness and ability to project power as a global security actor in the years ahead. The European debt crisis comes amid already long-standing U.S. concerns about a downward trend in European defense spending and shortfalls in European defense capabilities. Not counting the United States, NATO militaries have about two million personnel in uniform, but some 70% of European military forces reportedly cannot be deployed abroad, and throughout the Afghanistan mission the European members of the alliance have struggled to maintain 25,000 to 40,000 troops in the field. In 2011, only three NATO allies exceeded NATO's informal goal of 2% of GDP for defense spending (Greece, the United Kingdom, and the United States). European militaries continue to be limited by shortfalls in key capabilities such as strategic air- and sealift, aerial refueling, and Intelligence, Surveillance, and Reconnaissance (ISR). Some analysts have long asserted that defense spending in many European countries is inefficient, with disproportionately high personnel costs coming at the expense of much-needed research, development, and procurement. Analysts also argue that the European defense industry remains fractured and compartmentalized along national lines; many believe that European defense efforts would benefit from a cooperative rationalization of defense-industrial production and procurement. In Chicago, the allies are expected to commit to a "Smart Defense" initiative that will call for cooperation, prioritization, and specialization in pursuit of needed defense capabilities. NATO officials are expected to announce up to 20 multinational defense projects in which assets are pooled or shared, including acquisition, training, force protection, ISR, and logistics cooperation initiatives. This effort to enhance defense capabilities is the latest in a number of post-Cold War NATO capabilities initiatives, each of which has had mixed success. In February 2012, Secretary General Rasmussen announced agreement on a key ISR project, the Alliance Ground Surveillance (AGS) system, through which a group of 13 allies will jointly acquire five high-altitude Global Hawk strategic reconnaissance drones that will be maintained by and made available to the entire alliance beginning in 2015. Acquisition of AGS, long a priority of successive U.S. Administrations, will give European alliance members a capability that only the United States currently possesses and that played a key role in the Libya operation. Additional projects expected to be highlighted in Chicago include interim capability for a NATO-wide territorial missile defense system (see "Missile Defense" below), and NATO's long-standing Baltic Air Policing Mission. In February 2012, NATO agreed to extend the air policing mission indefinitely, subject to periodic review. Allies may also be asked to take bolder spending decisions in terms of phasing out what some perceive as unnecessary national "legacy" capabilities in order to fund collective alliance priorities. For example, U.S. officials have commended a Dutch decision to disband its army tank battalions and invest the savings in ballistic missile defense radars to be placed on Dutch frigates as part of a NATO-wide missile defense capability. Secretary General Rasmussen has announced plans for a parallel initiative to "Smart Defense," dubbed the "Connected Forces Initiative" (CFI). The goal is to enhance the capacity of military personnel from NATO member states to work together, through a focus on education and training, increased joint exercises, and better use of technology. A key element of the initiative is to increase joint exercises through the NATO Response Force (NRF), a multinational rapid reaction force of about 13,000, comprised of land, air, maritime, and special forces components. U.S. officials have said that combat units from an American-based brigade will rotate through Europe to train with the NRF after the planned withdrawal of two Brigade Combat Teams from Europe. The Obama Administration and other allied governments have pointed to NATO's 2011 mission in Libya as a positive example of transatlantic defense cooperation in which European allies and partners were not only centrally relevant, but in which they took the leading role—the mission was the first in NATO's history in which the United States did not lead military operations. At the same time, the Libya mission also exposed significant shortfalls in allied capabilities. According to U.S. officials, in Libya, the United States had to make up for a shortage of well-trained targeting specialists and shortages of key supplies and munitions in order to keep the operation going. Perhaps more importantly, European allies lacked critical enabling capabilities such as the aforementioned aerial refueling tankers and ISR. The United States reportedly supplied nearly half of the ISR aircraft in the mission and the vast majority of analytical capability. Recent reports indicate that even with U.S. help, NATO had only about 40% of the aircraft needed to intercept electronic communications in Libya. Some allied officials and observers argue that despite the criticism and shortcomings, the forces of key European allies still rank among the most capable militaries in the world; this assessment remains particularly true for France and the UK, which rank third and fourth, respectively, in global defense expenditure. Many European allies have undertaken significant defense transformation initiatives in recent years, and the EU has been exploring possibilities for greater defense integration and pooling of assets as a possible solution to the resource-capability crunch. NATO Secretary General Rasmussen and others have argued that the economic constraints facing allied governments could present an opportunity for European defense because it could help overcome long-standing political obstacles to cooperation initiatives and reforms that many have long argued are necessary in any case. In Lisbon, allies agreed to launch a Deterrence and Defense Posture Review (DDPR) that would further examine NATO's readiness and ability to address potential threats against the alliance. The results of the DDPR are expected to be presented to alliance leaders at the Chicago Summit. By most accounts, consultations in the DDPR have been "dynamic and extremely delicate," characterized by disagreements within the alliance about the future role of nuclear weapons in NATO. In testimony to Congress in November 2011, the State Department's Undersecretary for Arms Control and International Security, Ellen Tauscher, reaffirmed the Administration's position that "NATO will remain a nuclear alliance as long as nuclear weapons exist," a position that was also articulated in the 2010 Strategic Concept. Nevertheless, given persistent debates within the alliance on the issue, observers do not expect the allies to make any significant changes regarding longer-term force posture at the Chicago Summit, but rather to task NATO headquarters to study the issue further. The current debate on the role of nuclear weapons in the alliance has focused on U.S. non-strategic nuclear weapons (sometimes called tactical nuclear weapons, or NSNW) in Europe. Since the end of the Cold War, the United States is reported to have drastically reduced the number of NSNW based in Europe, but an estimated 150-200 reportedly remain deployed in five allied countries (Belgium, Germany, Italy, the Netherlands, and Turkey). The congressionally mandated Strategic Posture Commission has estimated that Russia, on the other hand. currently has around 3,800 operational non-strategic nuclear weapons. NATO's Strategic Concept states that "deterrence, based on an appropriate mix of nuclear and conventional capabilities, remains a core element of our overall strategy," and reflects the Administration's position that NATO will remain a nuclear alliance as long as nuclear weapons continue to exist. Proponents of NATO's current nuclear force posture support this view, highlighting both the need for a nuclear deterrent in a world where nuclear weapons continue to pose a security threat and the need to reassure member states for whom NATO's nuclear umbrella remains a vital component of national security. Some European leaders, however, have called for the removal of U.S. non-strategic nuclear weapons from European soil. Some members of the German government have been particularly vocal on the issue. Among other things, they argue that "the rationale for [U.S. nuclear] deployment expired with the collapse of the Warsaw Pact…and nuclear weapons based in Europe have little or no role to play in countering terrorism, the most likely external security threat to the alliance." In what could be a reflection of these views, NATO's Strategic Concept also alludes to the possibility of further reductions in nuclear weapons, both within the alliance and globally, in the future. In the document, the allies pledge to "seek to create the conditions for further reductions [of nuclear weapons] in the future," indicating that the goal in these reductions should be to "seek Russian agreement to increase transparency on its nuclear weapons in Europe and relocate these weapons away from the territory of NATO members." NATO's partnerships with non-NATO member states and other multilateral institutions are the third main agenda item at the Chicago Summit. U.S. and NATO officials increasingly emphasize the importance of working with regional and international partners to realize shared security objectives. They range from regional partners in the Mediterranean and the broader Middle East—including key contributors to the 2011 Libya operation—to partners on the other side of the globe, such as Australia, Japan, and South Korea. U.S. officials underscore that 22 non-NATO members are participating in NATO's Afghanistan mission, both in military operations and through significant financial contributions. Some analysts note that as NATO continues to face security challenges outside the Euro-Atlantic region, it could increasingly rely on the assistance of regional partners. In addition, the allies may want to enhance coordination with European partners, such as Sweden and Finland, which have been significant contributors to NATO operations, but are not members of NATO due primarily to political and historical reasons. NATO's 2010 Strategic Concept identifies the development of partnerships as a key security task for the alliance. In Lisbon, the allies launched a reform of NATO's partnership policy, intended to make "dialogue and cooperation more inclusive, flexible, meaningful and strategically oriented." A key aim of the ongoing reform of NATO's partnership programs is to streamline several distinct partnership initiatives and develop more flexible formats for the alliance to engage with partners. Currently, the alliance engages in relations with non-NATO members through at least four different programs: the 50-nation Euro-Atlantic Partnership Council and the related Partnership for Peace Program of bilateral cooperation with individual Euro-Atlantic countries; the Mediterranean Dialogue with countries in the southern Mediterranean; the Istanbul Cooperation Initiative with countries from the Gulf region; and relations with so-called "global partners" outside the Euro-Atlantic region, such as Australia, Japan, and New Zealand. Under reforms endorsed by NATO foreign ministers in April 2011, all NATO partners will have access to approximately 1,600 partnership activities laid out in a streamlined "Partnership and Cooperation Menu" (PCM), with an emphasis on training and support for security sector reform. NATO is also developing more flexible formats for cooperation among groups of partners working together to confront security issues beyond the existing partnership frameworks. This includes, for example, counter-piracy operations and cybersecurity. Relations with Russia are a central component of debates over NATO's future. That said, NATO-Russia relations are not expected to figure prominently on the Chicago Summit's agenda, especially since Russian President Vladimir is not attending the meeting. Russian representatives reportedly have been invited to attend discussions on Afghanistan, but their participation has not been confirmed. Some observers view the diminished level of Russian participation in Chicago as a telling sign of ongoing disagreements between the two sides on issues such as NATO's planned territorial missile defense system for Europe and Georgia's territorial integrity. Over the past several months, and particularly during Russia's recent election campaign, Russian leaders have engaged in what some consider hostile rhetoric toward NATO. Some NATO member states have criticized the Russian government's treatment of political protesters, resulting in angry responses from Moscow. During a meeting in Moscow on missile defense in early May 2012, Russian Chief of General Staff Nikolai Makarov reportedly suggested that Russia could use preemptive force against NATO missile defense installations if NATO moves forward with its missile defense plans without an agreement of cooperation with Russia. Secretary General Rasmussen and other allied leaders acknowledge these disagreements, but emphasize that the two sides are cooperating successfully in a range of areas, including in Afghanistan, joint counter-terrorism exercises, countering piracy, and counter-narcotics. NATO and U.S. officials highlight Afghanistan as a key example of the benefits of heightened NATO-Russia cooperation. Russia has allowed the use of air and land supply routes on its territory for the NATO mission and has agreed to bolster training for Afghan and regional counter-narcotics officers. According to U.S. officials, over 42,000 containers of cargo have transited Russia as a result of the agreement. The two sides are currently negotiating an expansion of the transit arrangement to allow for increased transit of NATO supplies out of Afghanistan during the ongoing transition. Russian helicopters, operated by civilian crews, have also begun providing transport in Afghanistan and the NATO-Russia Council established a Helicopter Maintenance Trust Fund in 2011. NATO and U.S. officials stress that they will continue to oppose Russian policies that they perceive as conflicting with the core values of the alliance. They say, for example, that NATO will not recognize a Russian sphere of influence outside its borders and will continue to reject Russia's recognition of Georgia's breakaway regions, Abkhazia and South Ossetia. There continues to be concern among some NATO allies that Russia has not changed its fundamental view of NATO as a security threat and that unresolved issues will continue to plague NATO-Russia relations. Observers and officials in some allied nations—notably the Baltic states and Poland—have at times expressed concern that NATO's reengagement with Russia could signal that the alliance is not serious about standing up to Russian behavior it has deemed unacceptable. In this vein, they have urged the United States to consider the interests and views of all NATO allies as it seeks to improve relations with Russia. As noted above, NATO enlargement is not expected to feature prominently on the Chicago Summit's agenda. Nevertheless, NATO maintains an "open door" policy on membership based on Article 10 of the alliance's founding treaty, which states that membership is open to "any European state in a position to further the principles of this Treaty and to contribute to the security of the North Atlantic Area." NATO's post-Cold War enlargement to Central and Eastern Europe was seen as a key factor in these countries' peaceful transition to democratic governance. However, in recent years, several allied governments have argued that NATO has enlarged too quickly, and that the alliance should agree on how to resolve a complex range of issues before taking in another group of new members. In April 2009, Albania and Croatia became the latest countries to join NATO. In 2008, the allies agreed that Macedonia meets the qualifications for NATO membership. In December 2009, Montenegro was offered a Membership Action Plan (MAP). In April 2010, Bosnia and Herzegovina was formally invited to join the MAP, but was told that its Annual National Program under the MAP would not be accepted until the country resolved an issue about the control of immovable defense property (mainly former military bases and barracks) on its territory. Little if any progress has been made in advancing Macedonia's stalled candidacy for NATO membership. As noted, in NATO summit communiqués since 2008, the allies have agreed that Macedonia meets the qualifications for membership. However, Greece has blocked a membership invitation due to a protracted dispute over Macedonia's name. The two sides have been unable to resolve the issue during talks sponsored by the U.N. In 2008, debate over whether to place Georgia and Ukraine in the MAP process caused controversy in the alliance. Although the allies have pledged that Georgia and Ukraine will eventually become NATO members, they have not specified when that might happen. The Russia-Georgia conflict and the renunciation of NATO membership aspirations by the current government in Ukraine appear to have diminished the short- and even medium-term membership prospects for the two countries. Most observers believe that the unresolved situation in South Ossetia and Abkhazia could continue to pose a major obstacle to possible Georgian membership for the foreseeable future. They contend that as long as the territorial dispute persists, some allies could oppose defining a specific timeline for membership. Congress has played an important role in guiding U.S. policy toward NATO and in shaping NATO's post-Cold War evolution. Members of the 112 th Congress have expressed interest in each of the key agenda items to be discussed in Chicago and, to varying degrees, have called on the Administration to advance specific policy proposals at the Summit. Proposed companion legislation in the House and the Senate— The NATO Enhancement Act of 2012 ( S. 2177 and H.R. 4243 )—endorses NATO enlargement to the Balkans and Georgia, reaffirms NATO's role as a nuclear alliance, and calls on the U.S. Administration to seek further allied contributions to a NATO territorial missile defense capability, and to urge NATO allies to develop critical military capabilities. In recent months, other Members of Congress have also called on the U.S. Administration and NATO to enhance efforts to bring Bosnia and Herzegovina, Georgia, Macedonia, and Montenegro into the alliance. In March 2012, a bipartisan group of 54 Members of the House signed a letter to President Obama urging him to ensure that Macedonia receives a formal invitation at the Chicago Summit to join NATO. In April 2012, Representative Carolyn Maloney introduced legislation apparently aimed at cautioning against formally inviting Macedonia before it resolves an ongoing dispute with Greece over Macedonia's name ( H.Res. 627 ). In the run-up to and aftermath of the Chicago Summit, Congress may want to consider a range of questions relating to NATO's current operations and activities and its longer term mission. These include the following. NATO's commitment to Afghanistan, both during the ongoing transition away from a primary emphasis on combat and after the transition. Some allied leaders—notably new French President François Hollande—have indicated a desire to accelerate the withdrawal of forces from Afghanistan. Congress may want to consider the implications of such decisions for NATO and U.S. security interests in Afghanistan. The allied commitment to sustaining the Afghan National Security Forces after 2014 could have particularly significant security implications for the United States, as could the extent of NATO's presence in the country after 2014. Allied military capabilities and burden-sharing within the alliance. In June 2011, then-U.S. Secretary of Defense Robert Gates lamented that many European allies are "unwilling to devote the necessary resources or make the necessary changes to be serious and capable partners in their own defense." Congress may want to consider the immediate and longer-term effects on alliance security of the continuing downward trend in European defense spending. Of particular concern could be the extent of the allied commitment to pooling and sharing resources in the framework of NATO's "Smart Defense" initiative and the extent to which European governments are consulting and coordinating with other allies when pursuing cuts to national defense budgets. In addition, if current trends in European defense spending and capabilities development continue over the medium term, how would this affect U.S. perceptions of NATO and the transatlantic security partnership? How would this affect U.S. pursuit of its security interests around the globe? Future NATO operations and allied military readiness. Some analysts assert that NATO member states would not support another "out of area" operation on the scale of the Afghanistan mission. Congress may want to consider the types of future military operations in which the alliance should be preparing to engage. What steps are being taken to ensure alliance readiness and interoperability? What effect will the planned withdrawal of two U.S. Army Brigade Combat Teams from Europe have on allied interoperability and alliance solidarity more generally? NATO's conventional and nuclear force posture. NATO allies continue to express divergent views on the appropriate force posture for the alliance. Congress may want to consider the implications for U.S. security interests of this ongoing debate within NATO. In particular, what role should U.S. non-strategic nuclear weapons play in alliance force posture? Do these weapons currently play an important deterrent role or is their presence primarily a symbol of U.S. commitment to NATO? What are the benefits of NATO's evolving territorial missile defense capability? What is the European allied commitment to that capability? NATO's relations with non-NATO member states and international organizations. Allied leaders and U.S. officials emphasize the importance of enhancing and expanding NATO's partnerships both within and outside the Euro-Atlantic region. The evolution of NATO's partnership policy could have significant political and operational implications for the alliance, including on its decision-making procedures and its force projection capabilities. Congress may want to consider the appropriate role of non-NATO members in the alliance's political structures and in allied operations. How would the increased participation of partners affect broader U.S. strategic interests? Should NATO seek to develop and/or enhance defense and security cooperation with the governments of Libya, Tunisia, Egypt, and other countries in the Mediterranean and broader Middle East region? Prospects and conditions for future NATO enlargement. Successive U.S. Administrations and some Members of Congress have emphasized the importance of NATO's "open door" membership policy. Congress may want to consider the possible implications of further NATO enlargement for U.S. and NATO security interests. What have been the costs and benefits of NATO's post-Cold War enlargement and what are the potential costs and benefits of possible future enlargement? Should there be a limit to NATO's "open door" policy? Should the alliance consider offering Russia the possibility of NATO membership? The U.S. Administration and some Members of Congress continue to view NATO as the world's preeminent military alliance and the cornerstone for transatlantic security cooperation. As NATO has evolved to confront a range of new and emerging security challenges, it has recorded some important achievements and faced considerable challenges. On the one hand, ongoing military operations in Afghanistan, the Balkans, and off the Horn of Africa demonstrate NATO's capacity to respond simultaneously to multiple security crises. On the other hand, severe budgetary constraints currently facing allied governments on both sides of the Atlantic have caused some to question NATO's ability to continue to sustain such an operational tempo. These budget constraints and public opposition in many European countries to military operations in Afghanistan could play a key role in shaping the scope of future NATO operations. As the alliance moves forward after the Chicago Summit, allied responses to these and the other challenges outlined above could be important factors in determining NATO's ability to meet and refine its strategic objectives.

Summary: NATO's 2012 summit of alliance heads of state and government is scheduled to take place in Chicago on May 20-21. U.S. and NATO officials have outlined what they expect to be the Summit's three main agenda items: Defining the next phase of formal transition in Afghanistan and shaping a longer term NATO commitment to the country after the planned end of combat operations by the end of 2014; Securing commitments to maintain and develop the military capabilities necessary to meet NATO's defense and security goals, including through a new "Smart Defense" initiative; and Enhancing NATO's partnerships with non-NATO member states. Although NATO is not expected to issue membership invitations to any of the four countries currently seeking NATO membership, it could reaffirm their commitment to do so in the future. Congress has played an important role in guiding U.S. policy toward NATO and shaping NATO's post-Cold War evolution. Members of the 112th Congress have expressed interest in each of the key agenda items to be discussed in Chicago. For example, proposed companion legislation in the House and Senate—The NATO Enhancement Act of 2012 (S. 2177 and H.R. 4243)—endorses NATO enlargement to the Balkans and Georgia, reaffirms NATO's role as a nuclear alliance, and calls on the U.S. Administration to seek further allied contributions to a NATO territorial missile defense system, and to urge NATO allies to develop critical military capabilities. In the run-up to and aftermath of the Chicago Summit, Congress may consider a range of issues relating to NATO's current operations and activities and its longer term mission. These include questions pertaining to: NATO's commitment to Afghanistan, both during the ongoing transition away from a primary emphasis on combat and after the transition; Allied conventional military capabilities and burden-sharing within the alliance; Future NATO operations and allied military readiness; NATO's future as a nuclear alliance; NATO's relations with non-NATO member states and multilateral organizations; and Prospects and conditions for future NATO enlargement.