アメリカ合衆国憲法第1条第8節において、「アメリカ合衆国議会が戦争を宣言する権限を持つべきである」とされるが、その節には宣戦布告する際に法律がどのような形式をとるべきか規定されておらず、憲法自体も「宣戦布告」という用語を使用していない。第1巡回区控訴裁判所（英語版）[2]は、Doe v. Bush（イラク戦争を巡る、匿名の市民と時の大統領ジョージ・W・ブッシュとの間の係争）において、10月決議（英語版）の条文自体が戦争の正当化と承認の枠組みを詳しく説明していると述べ[3]、事実上、戦争の宣言には議会の承認で事足りるとし、一部の人から議会による正式な宣戦布告と見なされるものは、憲法により義務付けられていないとされた。
Force withdrawn after six months. However, the Joint Resolution was likely used to authorize the Pancho Villa Expedition. In the Senate, "when word reached the Senate that the invasion had gone forward before the use-of-force resolution had been approved, Republicans reacted angrily" saying it was a violation of the Constitution, but eventually after the action had already started, a resolution was passed after the action to "justify" it since Senators did not think it was a declaration of war.[20][21]
The Global War on Terror is ongoing. The War in Afghanistan (2001–2021), that was carried out by the United States under the Global War on Terror's general authorization for use of military force, came to an end on August 30, 2021 with the total withdrawal of the American Forces from Afghanistan under the terms of the Doha Peace Agreement signed on February 29, 2020. The U.S. disengagement from Afghanistan resulted in the Fall of Kabul to the Taliban on August 15, 2021 and in a broad re-establishment of the status quo ante bellum. The U.S. backed Islamic Republic of Afghanistan collapsed even before the completion of the American withdrawal, and the Taliban victory led to the restoration of the Islamic Emirate of Afghanistan.
Other U.S. military campaigns that are legally based on the Global War on Terror's general authorization for use of military force include the ongoing American-led intervention in the Syrian civil war that was initiated on September 22, 2014 under President Barack Obama's administration. In spite of a significant drawdown of U.S. ground forces in Syria at the direction of President Donald Trump in 2019, the United States retains a residual presence of about 600 military personnel in Syria, and continues to conduct airstrikes against Iranian-supported militias as of 2021.
^Whereas the Government of Germany has formally declared war against the government and the people of the United States of America... the state of war between the United States and the Government of Germany which has thus been thrust upon the United States is hereby formally declared. The War ResolutionArchived December 5, 2006, at the Wayback Machine.
