	Introduction

Renewed attention to the role of Congress in the termination of treaties and other international agreements has arisen in response to President Donald J. Trump's actions related to certain high-profile international commitments. This report examines the legal framework for withdrawal from international agreements, and it focuses specifically on two pacts that may be of interest to the 115 th Congress: the Paris Agreement on climate change and the Joint Comprehensive Plan of Action (JCPOA) related to Iran's nuclear program. Although the Constitution sets forth a definite procedure whereby the President has the power to make treaties with the advice and consent of the Senate, it is silent as to how treaties may be terminated. Moreover, not all pacts between the United States and foreign nations take the form of Senate-approved, ratified treaties. The President commonly enters into binding executive agreements, which do not receive the Senate's advice and consent, and "political commitments," which are not legally binding, but may carry significant political weight . Consequently, the legal regime governing withdrawal under domestic law may differ in meaningful ways from the procedure for withdrawal under international law. And the domestic withdrawal process may be further complicated if Congress has enacted legislation implementing an international pact into the domestic law of the United States. Under the domestic law of the United States, a treaty is an agreement between the United States and another state that does not enter into force until it receives the advice and consent of a two-thirds majority of the Senate and is subsequently ratified by the President. Withdrawal from Treaties Under Domestic Law

Unlike the process of terminating executive agreements, which has not generated extensive opposition from Congress, the constitutional requirements for the termination of Senate-approved, ratified treaties have been the subject of occasional debate between the legislative and executive branches. . . has involved mutual action by the executive and legislative branches." Withdrawal from the Paris Agreement

On June 1, 2017, President Trump announced that he intends to withdraw the United States from the Paris Agreement—a multilateral, international agreement intended to reduce the effects of climate change by maintaining global temperatures "well below 2°C above pre-industrial levels[.]" Article 28 of the Paris Agreement provides that any party that withdraws from the UNFCCC shall be considered also to have withdrawn from the Paris Agreement. The Trump Administration, however, has not announced that it intends to take action with respect to the UNFCCC. Therefore, at present, the United States remains a party to the subsidiary Paris Agreement until Article 28's withdrawal procedure is complete—albeit one that has announced its intention to withdraw once it is eligible to do so. As discussed in more detail below, the President's certification decisions did not automatically terminate the United States' participation in the JCPOA or re-impose lifted sanctions, even though the President stated that he may take these actions in the future and may have domestic legal authority to do so unilaterally. To the extent the JCPOA is correctly understood as a nonbinding political commitment, international law would not prohibit President Trump from withdrawing from the plan of action and reinstating certain sanctions that had been previously imposed under U.S. law, but there may be political consequences for this course of action. As a matter of international law, by contrast, termination of the JCPOA or re-imposition of sanctions (either by Congress or the President alone) could implicate the question of whether Resolution 2231 converted the JCPOA's nonbinding political commitments into obligations that are binding under the U.N. Charter.
The legal procedure through which the United States withdraws from treaties and other international agreements has been the subject of long-standing debate between the legislative and executive branches. Recently, questions concerning the role of Congress in the withdrawal process have arisen in response to President Donald J. Trump's actions related to certain high-profile international commitments. This report outlines the legal framework for withdrawal from international agreements under domestic and international law, and it applies that framework to two pacts that may be of significance to the 115th Congress: the Paris Agreement on climate change and the Joint Comprehensive Plan of Action (JCPOA) related to Iran's nuclear program.
Although the Constitution sets forth a definite procedure whereby the Executive has the power to make treaties with the advice and consent of the Senate, it is silent as to how treaties may be terminated. Moreover, not all agreements between the United States and foreign nations take the form of Senate-approved, ratified treaties. The President also enters into executive agreements, which do not receive the Senate's advice and consent, and "political commitments" that are not binding under domestic or international law. The legal procedure for withdrawal often depends on the type of agreement at issue, and the process may be further complicated when Congress has enacted legislation to give the international agreement domestic legal effect.
On June 1, 2017, President Trump announced that he intends to withdraw the United States from the Paris Agreement—a multilateral, international agreement intended to reduce the effects of climate change. Historical practice suggests that, because the Obama Administration considered the Paris Agreement to be an executive agreement that did not require the Senate's advice and consent, the President potentially may claim authority to withdraw without seeking approval from the legislative branch. By its terms, however, the Paris Agreement does not allow parties to complete the withdrawal process until November 2020, and Trump Administration officials have stated that the Administration intends to follow the multiyear withdrawal procedure. Consequently, absent additional action by the Trump Administration, the United States will remain a party to the Paris Agreement until November 2020, albeit one that has announced its intent to withdraw once it is eligible to do so.
The Trump Administration has not withdrawn the United States from the JCPOA, but the President has stated he intends do so unless the plan of action is renegotiated. When the Obama Administration concluded the JCPOA, it treated the plan of action as a non-binding political commitment. To the extent this understanding is correct, President Trump's ability to withdraw from the JCPOA would not be restricted by international or domestic law. However, some observers have suggested that U.N. Security Council Resolution 2231 subsequently converted at least some provisions in the JCPOA into obligations that are binding under international law. As a result, withdrawal from the JCPOA could implicate a complex debate over the plan of action's status in international law.
As a matter of domestic law, the President and Congress have authority to reassert sanctions lifted pursuant to U.S. pledges made in the JCPOA if they deem the reinstitution of such sanctions to be appropriate, even if such action resulted in a violation of international law. Several possible domestic legal avenues exist to re-impose sanctions, some of which would involve joint action by the President and the legislative branch, and others that would involve decisions made by the President alone.