The President and Congress have historically played different roles when sending U.S. troops into hostile situations. The President has the power under Article II, Section 2, of the Constitution to use the Armed Forces to repel attacks. Congress under Article I, Section 8, has the power to declare war and raise and support the Armed Forces. The War Powers Resolution was enacted to ensure that the President and Congress share decisions where U.S. troops may become involved in hostilities. This sharing of power has often resulted in controversy, particularly when troops are sent into situations where there has not been a formal declaration of war. In most instances, Congress has used its legislative prerogatives through funding mechanisms or declarations of policy either to affirm or to place limits on presidential action. In three instances, Congress has authorized the use of military force in advance of hostilities: the Persian Gulf War (1991), military operations in Afghanistan (2001), and the "use of force against Iraq" resolution (2002). In each case, however, the President has maintained that while he may have sought congressional consultation and support, the President has the constitutional authority as Commander in Chief to use force, including the Armed Forces of the United States, to protect U.S. national security interests. Additionally, the executive branch has long viewed congressional enactment of defense appropriations bills as de facto authorization for operations funded under those measures, although Congress has often included provisions stating that no separate authorization for the use of force is implied by the appropriation of funds. Related CRS products CRS Report RL31133, Declarations of War and Authorizations for the Use of Military Force: Historical Background and Legal Implications , by Jennifer K. Elsea and Matthew C. Weed. CRS Report R42699, The War Powers Resolution: Concepts and Practice , by Matthew C. Weed. CRS Report R42738, Instances of Use of United States Armed Forces Abroad, 1798-2018 , by Barbara Salazar Torreon and Sofia Plagakis. This report describes the congressional debate that often surrounds the issue of employing the U.S. military abroad. Initially written in response to a congressional request for a list of votes on this topic from 1982-1992, this report has been updated as needed since that time. The floor votes included are those directly related to the use and funding of U.S. troops abroad, often in the context of the War Powers Resolution, or to their continued presence or withdrawal. The laws, bills, and resolutions below are listed in the chronological order of the votes that were held. Links to the actual roll call votes are provided, when available (since 1990 in the House and 1989 in the Senate). These links include each Member's yea or nay vote. In some cases, House or Senate votes are voice votes, and, thus, no roll call vote exists. Moreover, the ultimate disposition of amendments listed in the report (i.e., whether such amendments were incorporated into any final law) may not be self-evident. Some amendments may appear as considered; some may have been further amended during subsequent proceedings or in conference; some may have been deleted in conference when one chamber receded from that amendment. In other instances, only one chamber of Congress may have voted on a particular measure; for example, a House or Senate simple resolution is a measure that expresses nonbinding opinions on policies or issues and is effective only in the chamber in which it is proposed. It does not require concurrence by the other chamber or approval by the President. On September 29, 1982, President Reagan deployed 1,200 marines to serve as part of a multinational observer force to restore the sovereignty of the Lebanese government. By March 30, 1984, the mission had ended. Related CRS products CRS Report R44759, Lebanon , by Carla E. Humud. On October 25, 1983, President Reagan sent U.S. Marines and Army troops to Grenada in order to protect American lives and restore law and order at the request of the Organization of Eastern Caribbean States. All U.S. troops were removed from Grenada by December 15, 1983. On December 20, 1989, President George H.W. Bush deployed 14,000 U.S. military forces to Panama in order to protect American lives, restore Panamanian democracy, and apprehend General Manuel Noriega. Congress did not immediately react to the situation, as the 101 st Congress, first session had ended on November 22, 1989; the second session of the 101 st Congress did not begin until January 23, 1990. The 14,000 U.S. troops were removed from Panama by February 13, 1990. Related CRS products CRS In Focus IF10430, Panama , by Mark P. Sullivan. CRS Report RL30981, Panama: Political and Economic Conditions and U.S. Relations Through 2012 , by Mark P. Sullivan. On August 2, 1990, Iraqi troops invaded Kuwait, seized its oil fields, ousted the Kuwaiti leadership, installed a new government in Kuwait City, and massed troops on the Saudi Arabian border. On August 9, President Bush reported that he had deployed U.S. troops to the region. Legislation in late 1990 (101 st Congress, second session) focused on imposing sanctions against Iraq, in seeking the withdrawal of Iraqi forces from the area, and in supporting the President in carrying out the provisions of the relevant United Nations Security Council resolutions. On January 12, 1991 (102 nd Congress, first session), the Congress authorized the "use of force" against Iraq in advance of the outbreak of hostilities with Iraq on January 16. Related CRS products CRS Report RS21513, Kuwait: Governance, Security, and U.S. Policy , by Kenneth Katzman. On December 10, 1992, President George H.W. Bush reported that he had deployed U.S. troops into Somalia on December 8, in response to United Nations Security Council Resolution 794, which authorized the Secretary General to "use all necessary means to establish as soon as possible a secure environment for humanitarian relief operations in Somalia" and to provide military forces for accomplishing this mission. U.S. troops were deployed to assist United Nations Forces in Somalia (UNOSOM) throughout 1993 and 1994, ending on March 3, 1995. Related CRS products CRS In Focus IF10155, Somalia , by Lauren Ploch Blanchard and Katherine Z. Terrell. CRS Report R45428, Sub-Saharan Africa: Key Issues and U.S. Engagement , coordinated by Tomas F. Husted. On October 20, 1993, President Bill Clinton reported that U.S. ships had begun enforcing a United Nations embargo against Haiti. On September 19, 1994, President Clinton had deployed 1,500 troops to Haiti to restore democracy; that level was ultimately increased to over 20,000. By March 21, 1995, U.S. troops were reduced to under 5,300 and incorporated into the United Nations Multinational Force in Haiti. By September 21, 1995, they were reduced to under 2,500 personnel. U.S. troops ended their deployment to Haiti by April 17, 1996. Related CRS products CRS Report R45034, Haiti's Political and Economic Conditions: In Brief , by Maureen Taft-Morales. Archived CRS Report RL32294, Haiti: Developments and U.S. Policy Since 1991 and Current Congressional Concerns , by Maureen Taft-Morales and Clare Ribando Seelke. The civil war in the former Yugoslav Republic of Bosnia-Herzegovina resulted in U.S. military participation in various efforts over several years to halt the fighting. The United States participated in both United Nations and NATO actions without explicit congressional authorization. Beginning in 1992, the United Nations Security Council adopted Resolution 770, which called on all nations to take "all measures necessary" to facilitate the delivery of humanitarian assistance to Sarajevo. On August 11, 1992, the Senate passed S.Res. 330 , which urged the President to work for such a resolution and pledged funds for participation, but also said that no U.S. military personnel should be introduced into hostilities without clearly defined objectives. On the same day, the House passed H.Res. 554 , which urged the Security Council to authorize measures, including the use of force, to ensure humanitarian relief. As the conflict in Bosnia continued and escalated over the next several years, U.S. troops were sent to participate in NATO and United Nations peacekeeping missions. Consequently, leaders in Congress began calling for greater congressional involvement in decisions. In 1994, for example, the Senate passed S. 2042 , which called for the United States to end unilaterally its arms embargo with Bosnia; the Senate also passed an amendment to S. 2042 which stated that no ground combat troops should be deployed to Bosnia unless previously authorized by Congress. The House did not act on the measure. With the signing of the Dayton Peace Agreement for Bosnia on December 14, 1995, NATO took over the ground operation from UNPROFOR (United Nations Protection Force). Consequently, in late 1995, over 20,000 U.S. combat troops were sent to Bosnia as part of the NATO-led peacekeeping force. In December 1995, Congress considered and voted on a number of bills and resolutions, but the House and Senate could not come to consensus on any single measure. In 1996, President Clinton agreed to provide up to 8,500 ground troops to participate in the NATO-led follow-on force in Bosnia termed the Stabilization Force (SFOR). Subsequent efforts by both the House and Senate to require the President to either limit funding for the Bosnia operations or to bring the troops home did not succeed. On March 18, 1998, for example, the House defeated by a vote of 193-225 H.Con.Res. 227 , which would have directed the President to remove U.S. Armed Forces from the Republic of Bosnia-Herzegovina, pursuant to Section 5(c) of the War Powers Resolution. On July 22, 2002, President Bush reported to Congress that U.S. Armed Forces contributions to SFOR in Bosnia-Herzegovina were approximately 2,400 personnel. U.S. troops ended their mission in Bosnia-Herzegovina when SFOR was replaced by the European Union Force (EUFOR Althea) in 2004. The following table includes legislation of what was introduced and voted on during the 102nd Congress-105th Congresses (1992-1998). Related CRS products CRS Insight IN10980, Postelection Issues in Bosnia and Herzegovina , by Sarah E. Garding. CRS Report RS21774, Bosnia and the European Union Military Force (EUFOR): Post-NATO Peacekeeping , by Julie Kim. CRS Report 96-723, Bosnia Implementation Force (IFOR) and Stabilization Force (SFOR): Activities of the 104th Congress , by Julie Kim. On March 24, 1999, President Clinton ordered U.S. military forces to begin air strikes against the Federal Republic of Yugoslavia (Serbia and Montenegro) in cooperation with the NATO-led operation. The strike was ordered in response to Yugoslavia's campaign of violence against ethnic Albanians in the province of Kosovo. On June 3, 1999, Yugoslavia agreed to a peace plan calling for withdrawal of Yugoslav forces from Kosovo to include an international peacekeeping force. On June 10, 1999, NATO air strikes were halted, and Yugoslav forces withdrew their military forces from Kosovo by June 20, 1999. Congress, while not authorizing directly, and in advance, this military action, introduced and voted on several legislative measures related to deployment of U.S. military forces for combat or peacekeeping in the Balkan region. The House adopted H.Con.Res. 42 on March 11, 1999, which authorized the President to send troops as peacekeepers; the Senate passed a non-binding resolution ( S.Con.Res. 21 ) on March 23, 1999, that expressed the sense of Congress that the President was authorized to conduct military air operations in cooperation with NATO allies against Yugoslavia. However, the House later defeated the Senate resolution, on April 28, 1999. Other House or Senate votes sent conflicting signals in addressing funding related to troop deployments in the region, declaration of war issues, and executive and congressional roles in sending U.S. military forces abroad. The following legislation is representative of what was introduced and voted on in the 106 th Congress. Related CRS products CRS Report R44979, Kosovo: Background and U.S. Relations , by Vincent L. Morelli. CRS Report R44955, Serbia: Background and U.S. Relations , by Vincent L. Morelli and Sarah E. Garding. CRS Report RL31053, Kosovo and U.S. Policy: Background to Independence , by Julie Kim and Steven Woehrel. CRS Report RL30127, Kosovo Conflict Chronology: September 1998 - March 1999 , by Julie Kim. On September 11, 2001, terrorists attacked the United States with a coordinated series of aircraft hijackings and suicide crashes into populated buildings. Two airplanes crashed into the twin towers of the World Trade Center in New York City, causing their complete destruction. Another airplane crashed into the Pentagon near Washington, DC, and a fourth airplane crashed in southwestern Pennsylvania (near Shanksville) after passengers attempted to take control of the aircraft in order to prevent it from crashing into an important symbol of democracy and freedom, perhaps in the Washington, DC, area. Over 3,000 people lost their lives in these terrorist attacks. Consequently, on September 14, 2001, Congress passed a joint resolution, which "authorizes the President to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations, or persons." It further states that the act is intended to constitute specific statutory authorization within the meaning of the War Powers Resolution. President George W. Bush signed the joint resolution into law on September 18, 2001. On October 9, 2001, President Bush reported in a letter to Congress that U.S. Armed Forces had begun combat action in Afghanistan against the Al Qaeda terrorists and their Taliban supporters starting at 12:30 p.m. (EDT) on October 7, 2001. Related CRS products CRS Report R43983, 2001 Authorization for Use of Military Force: Issues Concerning Its Continued Application , by Matthew C. Weed. On October 10, 2002, after several days of debate, the House passed H.J.Res. 114 , which authorized the use of military force against Iraq. The Senate had considered its own measure, S.J.Res. 45 , beginning on October 3, but indefinitely postponed it, and instead passed H.J.Res. 114 on October 11, 2002. As enacted into law, the joint resolution provides authorization for the use of military force against Iraq and expresses support for the President's efforts to (1) strictly enforce through the United Nations Security Council all relevant Security Council resolutions regarding Iraq; and (2) obtain prompt and decisive action by the Security Council to ensure that Iraq abandons its strategy of delay, evasion, and noncompliance and promptly and strictly complies with all relevant Security Council resolutions. In addition, it authorizes the President to use the U.S. Armed Forces to (1) defend U.S. national security against the continuing threat posed by Iraq; and (2) enforce all relevant Security Council resolutions regarding Iraq. It directs the President, prior to or as soon as possible (but no later than 48 hours) after exercising such authority, to make available to the Speaker of the House of Representatives and the President pro tempore of the Senate his determination that (1) reliance on further diplomatic or peaceful means alone will not achieve the above purposes; and (2) acting pursuant to this joint resolution is consistent with the United States and other countries continuing to take necessary actions against international terrorists and terrorist organizations, including those who planned, authorized, committed, or aided the terrorist attacks of September 11, 2001. It declares that this section is intended to constitute specific statutory authorization for use of the Armed Forces, consistent with the requirements of the War Powers Resolution. Finally, it requires the President to report to Congress at least every 60 days on matters relevant to this resolution. The war with Iraq (Operation Iraqi Freedom) began on March 19, 2003, with an aerial attack against a location where Iraqi President Saddam Hussein was suspected to be meeting with top Iraqi officials. U.S. and British troops entered Iraq on March 20, 2003, and while the invasion encountered resistance, particularly in its early stages, U.S. forces had largely gained control of Baghdad by April 9, 2003. The northern cities of Kirkuk and Mosul fell shortly afterward, and on April 14, 2003, U.S. troops entered Tikrit, Saddam's birthplace and the last major population center outside coalition control. On April 15, 2003, President George W. Bush declared that "the regime of Saddam Hussein is no more." U.S. military operations against Al Qaeda and Taliban forces in Afghanistan proceeded pursuant to the 2001 Authorization for Use of Military Force from October 2001 onward. U.S. military operations in Iraq proceeded pursuant to the 2002 Authorization for Use of Military Force in Iraq from March 2003 onward. On March 25, 2003, President George W. Bush requested $74.8 billion in the FY2003 Emergency Supplemental for the ongoing military operations in Iraq, postwar occupation, reconstruction and relief in Iraq, and international assistance to countries contributing to the war in Iraq or the global war on terrorism. The cost of the continued U.S. presence in Afghanistan and additional funds for homeland security were also included. H.R. 1559 , enacted into law as P.L. 108-11 on April 16, 2003, provided $78.49 billion in funding for these purposes. The Senate passed H.R. 1559 in lieu of its version, S. 762 , by unanimous consent. On September 17, 2003, President Bush formally requested an additional $87 billion for the ongoing military operations and for reconstruction assistance in Iraq, Afghanistan, and elsewhere. H.R. 3289 (FY2004 supplemental appropriations for Iraq, Afghanistan, and the global war on terrorism) was enacted into law as P.L. 108-106 on November 6, 2003, providing $87.5 billion in funding. The House approved the conference agreement by a roll call vote on October 31, 2003, and the Senate approved the conference agreement by voice vote on November 3, 2003. Earlier, on October 17, 2003, the Senate had approved its own version of the measure, S. 1689 , but vitiated its passage and returned the bill to the Senate Calendar. Related CRS products CRS Report R45025, Iraq: Background and U.S. Policy , by Christopher M. Blanchard. CRS Report RL30588, Afghanistan: Post-Taliban Governance, Security, and U.S. Policy , by Kenneth Katzman and Clayton Thomas. CRS Report R41070, Al Qaeda and Affiliates: Historical Perspective, Global Presence, and Implications for U.S. Policy , coordinated by John W. Rollins. The 2011 uprising against Libyan dictator Muammar Qadhafi prompted calls for Western military assistance to the rebels, initially in the form of a no-fly zone to prevent regime aircraft from attacking rebel forces and civilians. As the revolt progressed, air strikes were conducted by U.S. and NATO forces against regime targets under Operation Odyssey Dawn and Operation Unified Protector. The Qadhafi government was overthrown and Qadhafi himself was killed, leading to the lifting of strict regime political control in Libya but also to an uncertain security environment in which rival militias competed in the absence of any strong central authority. U.S. military operations began in March 2011 and ended in October 2011. A September 11, 2012, armed attack on a U.S. diplomatic compound in Benghazi, Libya resulted in the deaths of four Americans, including the U.S. ambassador. Related CRS products CRS Report RL33142, Libya: Transition and U.S. Policy , by Christopher M. Blanchard . What began as protests, then an internal armed uprising in Syria in 2011 became a broader conflict, with various factions of Syrian rebels and foreign fighters joined in combat with each other as well as with the forces of the Asad regime, itself aided by fighters from outside Syria. In summer 2013 the Obama Administration announced that the U.S. intelligence community had determined "with high confidence" that the Asad regime had used chemical weapons attacks against its own people, resulting in mass casualties. The United States has been providing nonlethal materiel support to selected opposition groups, and a congressionally authorized U.S. train-and-equip program continues. See section below, " Military Action against the Islamic State (IS, ISIS, ISIL) ." Related CRS products CRS Report RL33487, Armed Conflict in Syria: Overview and U.S. Response , coordinated by Carla E. Humud. One group rose to prominence in the fighting against the Assad regime: the self-proclaimed "Islamic State" (IS), also known as ISIS (Islamic State in Iraq and Syria) and ISIL (Islamic State in Iraq and the Levant). A lineal descendant or continuation of the insurgent group al-Qaeda in Iraq, some of its senior operatives gained experience fighting American forces in Iraq. Particularly noted for sophisticated online media releases and extremely brutal tactics, IS in its self-released videos showed numerous massacres and beheadings, including those of a number of captured Westerners. It made significant territorial gains in Syria and also in Iraq, where its forces captured refineries and banks, thereby acquiring a self-financing capacity. The Iraqi military suffered high personnel losses through casualties and desertions, as well as enormous losses of materiel. After a series of online releases depicting the beheadings of American captives of IS, and in the wake of the success of the IS campaign in Iraq and Syria, President Obama authorized a program of aid to anti-IS forces, particularly the Iraqi military and the Kurds. In cooperation with a coalition of allies, he ordered air strikes designed to assist Iraqi and Kurdish forces battling IS and degrade IS military capabilities. IS has suffered extensive territorial losses in the combined campaign and today controls far less territory in Syria and Iraq than at the height of its power, but the potential for terrorist acts committed by IS foreign fighters returning to their countries of origin is a matter of concern for antiterrorism and police authorities. Related CRS products CRS Report R43612, The Islamic State and U.S. Policy , by Christopher M. Blanchard and Carla E. Humud. CRS Report R43760, A New Authorization for Use of Military Force Against the Islamic State: Issues and Current Proposals , by Matthew C. Weed. CRS Report R44135, Coalition Contributions to Countering the Islamic State , by Kathleen J. McInnis. CRS In Focus IF10604, Al Qaeda and Islamic State Affiliates in Afghanistan , by Clayton Thomas. Beginning in March 2015, Saudi Arabia and a coalition of partner countries (including the United Arab Emirates, Bahrain, Kuwait, Egypt, Jordan, Morocco, Senegal, and Sudan) engaged in conflict in Yemen against the Ansar Allah/Houthi movement and followers of the late president of Yemen, Ali Abdullah Saleh. The United States has been providing logistical and intelligence support, for a time including air-to-air refueling. Refueling operations ended in early November 2018. Civilian casualties in the conflict have been a matter of concern and congressional debate, along with humanitarian conditions in general in Yemen. Related CRS Products CRS Report R43960, Yemen: Civil War and Regional Intervention , by Jeremy M. Sharp. CRS Report R45046, The War in Yemen: A Compilation of Legislation in the 115th Congress , by Jeremy M. Sharp and Christopher M. Blanchard. CRS Report R42738, Instances of Use of United States Armed Forces Abroad, 1798-2018 , by Barbara Salazar Torreon and Sofia Plagakis. CRS Report RL32492, American War and Military Operations Casualties: Lists and Statistics , by Nese F. DeBruyne. CRS Report RL31133, Declarations of War and Authorizations for the Use of Military Force: Historical Background and Legal Implications , by Jennifer K. Elsea and Matthew C. Weed. CRS Report R42699, The War Powers Resolution: Concepts and Practice , by Matthew C. Weed. Legislative Information System (LIS) of the U.S. Congress at http://www.congress.gov/ . Congressional Quarterly searchable online floor vote database at http://www.cq.com . Congressional Quarterly Almanac . Washington, CQ Press. Annual. CQ Weekly . Washington, CQ Press. Various issues. 

Summary: This report summarizes selected congressional roll call votes related to instances in which U.S. Armed Forces have been sent abroad in potentially hostile situations. These votes reflect the type of congressional actions that observers maintain bear directly on issues affecting policy and the funding of troops abroad, often in the context of the War Powers Resolution, continued presence or withdrawal of troops, and the "use of force." The cases of Lebanon (1982-1983), Grenada (1983), Panama (1989), the Persian Gulf War (1990-1991), Somalia (1992-1995), Haiti (1993-1996), Bosnia (1992-1998), Kosovo (1999), the terrorist attack against the United States (2001) (including the use of U.S. Armed Forces in Afghanistan), and the use of U.S. Armed Forces against Iraq (2002-2003) and Iraq and Afghanistan (2001-Present) are examined, as are the revolution in Libya and its aftermath, the uprising and war in Syria, and military action against the self-proclaimed Islamic State (IS a.k.a, ISIS/ISIL). The roll call votes that are available online (since 1990 in the House and 1989 in the Senate) are hyperlinked in the text.