President Donald Trump has waged an unprecedented war on international law, withdrawing the United States from numerous international arrangements over the course of his presidency. In a previous article, I cataloged the wide array of international agreements from which the Trump administration has withdrawn. If Joe Biden is elected on November 3 and becomes president in January 2021, what can he do to repair the damage? Here, I seek to lay out the options.

In Part I, I placed the international arrangements from which Trump has withdrawn into three broad categories: (1) nonbinding arrangements and international organizations, (2) executive agreements, and (3) Article II treaties. Rejoining each type of arrangement requires different procedures and poses different legal and political challenges, which I outline here. (This analysis focuses on instances where withdrawal will have been completed by the time a new president enters office. For international agreements where withdrawal will have been announced but not yet effective, such as the World Health Organization, the new president need only provide proper notice that the United States does not intend to withdraw.)

Nonbinding Arrangements & International Organizations

Let’s start with the easiest category: nonbinding arrangements. Nonbinding arrangements—political commitments, bilateral joint statements, and others—are not, as a matter of domestic or international law, international treaties. As such, they are generally considered to fall exclusively within the scope of the president’s unilateral authority—both as to their creation and withdrawal from them.

As a legal matter, a new administration could reestablish U.S. commitment to the non-binding compacts and other arrangements listed in the previous article without congressional approval, unless there is specific domestic law to the contrary. For instance, if the Joint Comprehensive Plan of Action (JCPOA) is re-negotiated before re-joining, it would likely be subject to the Iran Nuclear Agreement Review Act of 2015’s provisions for congressional review. In addition, an agreement that requires funds may be subject to available appropriations. With respect to the United Nations Relief and Works Agency (UNRWA), for instance, Congress could appropriate funds specifically for UNRWA, or a new administration could use the State Department’s humanitarian funds for this purpose again, unless there are restrictions barring such use. There may also be congressional relations, policy, and other non-legal implications of rejoining these arrangements that a new administration would want to consider. Finally, rejoining arrangements may require the consent of the other countries involved, depending on the terms of the arrangement itself.

All of these specific domestic law concerns are important, of course. But they should not obscure that, as a general matter, the president has a great deal of latitude to act in this area. As long as an arrangement is nonbinding, there is no blanket requirement that it be subject to congressional oversight, review, or approval.

Executive Agreements

As explained in Part I, executive agreements, which create binding legal obligations on the United States under international law, are commonly grouped into one of three categories based on the type of authorization that supports the agreement: (1) a “sole executive agreement” concluded by a president on his or her own constitutional authority; (2) an “ex ante congressional-executive agreement” authorized in advance by statute, treaty, or prior international agreement; or (3) an “ex post congressional-executive agreement” approved by Congress after it is negotiated, usually through ordinary legislation.

The agreements in the first two of these categories do not require congressional consent or approval for the president to join or rejoin as long as authority to conclude them still exists. A subsequent president may therefore simply rejoin an agreement from which a predecessor withdrew, unless the authority under which it was initially concluded no longer exists—for example, the statute that authorized an ex ante agreement has been repealed in the interim. Of course, withdrawal from a bilateral agreement ends the agreement itself, so the president would have to work with the other party to reanimate the agreement—or create a new one in its place. Some other agreements may require consent of the parties for the United States to be permitted to rejoin.

To take a concrete example, a new administration could, as a matter of domestic law, unilaterally rejoin the Paris Agreement on climate change, which was largely concluded as an executive agreement authorized in advance by a prior international treaty or agreement. The agreement would enter into force for the United States after thirty days. As part of the rejoining process, the United States would also have to submit a new Nationally Determined Contribution (NDC).

For executive agreements that require congressional approval before the president may ratify (ex post congressional-executive agreements), there is less clarity. I have argued that such executive agreements are fully interchangeable with Article II treaties in nearly every respect. If that is right (and not everyone agrees it is), that would suggest that the options for withdrawal (and the options for rejoining) are similar to those for Article II treaties, which are reviewed below. Notably, however, the legislation that authorized participation in the agreement may establish conditions or limits on withdrawal that would arguably be binding. The United Nations Educational Scientific and Cultural Organization Constitution and World Health Organization Constitution were both concluded as ex post congressional-executive agreements and therefore options for rejoining them once withdrawal is completed are similar to those for Article II treaties.

Article II Treaties

Article II of the Constitution states that the president “shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur.” It does not specify how Article II treaties may be “unmade.” Some have argued that because the president has the power not to ratify a treaty even after the Senate’s consent has been given, the president must have the parallel authority to withdraw that ratification regardless of the Senate’s position on withdrawal. The Restatement (Fourth) of Foreign Relations Law § 313 endorses this view, stating that,

According to established practice, the President has the authority to act on behalf of the United States in suspending or terminating U.S. treaty commitments and in withdrawing the United States from treaties, either on the basis of terms in the treaty allowing for such action (such as a withdrawal clause) or on the basis of international law that would justify such action.

This view has never been formally upheld by the courts and has been challenged by scholars, though most recent scholarship has concluded that the executive has effective unilateral power to suspend and end treaties. Yet others have concluded that there is no one right answer.

The Senate, perhaps not surprisingly, opposes the idea that the president can unilaterally withdraw from a ratified treaty. The Senate Foreign Relations Committee has previously contended that the termination of treaties requires the participation of the Senate or Congress. In 1856, a Senate report explained that “the President and Senate, acting together, [are competent] to terminate [a treaty],” a position echoed in a 1979 report rejecting “the notion advanced by Administration witnesses that the President possesses an ‘implied’ power to terminate any treaty, with any country, under any circumstances, irrespective of what action may have been taken by the Congress by law or by the Senate in a reservation to that treaty.” A report prepared in 2001 by the Senate Foreign Relations Committee similarly concluded that whether termination of a treaty “requires conjoint action of the political branches remains . . . a live issue which the Supreme Court has sidestepped in the past.” Yet it admitted that “[a]s a practical matter . . . the President may exercise this power since the courts have held that they are conclusively bound by an executive determination with regard to whether a treaty is still in effect.” The courts have twice declined to intervene to prevent unilateral withdrawal from a treaty by the president on the grounds that the challenge to the president’s authority posed a political question, among other reasons.

In practice, presidents have unilaterally terminated Article II treaties, though none as aggressively as the Trump. All of the treaties outlined in Part I were terminated by the Trump administration without seeking concurrence or approval from Congress.

There are three main options for rejoining (as noted earlier, these options likely also apply to ex post congressional-executive agreements):

1. Seek to join or rejoin through the ordinary process.

One at least theoretical option would be to rejoin the treaties and ex post executive agreements from which the Trump administration withdrew by going back through the ratification or approval process. This is highly unlikely to be a practical solution, especially for Article II treaties. Gaining the “advice and consent” for Article II treaties requires a favorable vote of two-thirds of the Senate—or 67 senators. I calculated in 2008 that, due to malapportionment in the Senate, senators representing only about 8 percent of the country’s population can halt a treaty. Even if the required number of votes could be assembled, the floor time required would be prohibitive, particularly given all the other priorities awaiting a new president.

2. Rejoin relying on the Senate’s (or Congress’) earlier consent.

Jean Galbraith and others have argued persuasively that there is an alternate path, which would be to simply, as Galbraith puts it, “treat the Senate’s pre-existing resolution of advice and consent as still operative. The President could therefore rejoin the international agreement as a treaty, but without having to go again to the Senate for advice and consent.” The same would be true for ex post congressional-executive agreements—Congress’ earlier consent would be treated as still operative. As Galbraith explains, the presumption in favor permitting the president to rejoin “would be overcome, however, if rejoining would be inconsistent with the language of the original resolution, with any modifications to this resolution made by two-thirds of the Senate, or with an intervening congressional statute.” The executive branch adopted this position with respect to at least one earlier executive agreement: President Ronald Reagan withdrew from UNESCO’s Constitution in 1984, and President George W. Bush rejoined in 2003, relying on the original congressional authorization, enacted into law in 1946. (Longtime State Department lawyer Susan Biniaz, made a similar argument for rejoining the United Nations Framework Convention on Climate Change if the Trump Administration withdrew from it at the 2017 Duke-Yale Foreign Relations Law Workshop.)

Galbraith argues that it is possible to rejoin a treaty by relying on previous advice and consent for reasons based “on these resolutions’ text, on broader constitutional practice, and on structural principles.” She notes that these resolutions rarely say that they become ineffective at a certain date, and in fact many presidents have ratified treaties in a Senate session that fell well after the advice and consent was given. For example, the Vienna Convention on Diplomatic Relations and its Optional Protocol were signed in 1961, received advice and consent in 1965, but were not ratified until 1972. Such a long delay suggests that, absent some intervening act by Congress, advice and consent does not expire. In contrast, regular statutes do expire under the Constitution if not signed and returned by the president in a set time within which Congress has adjourned. Additionally, Galbraith argues that because the president can unilaterally decide on ratification, he can withdraw from a treaty without “effectively eras[ing] a Senate resolution, unless the Senate or Congress expressly authorized this result.”

There are cases where the legal argument for a unilateral decision to rejoin would be challenging, if not impossible. For example, rejoining under the original resolution is not possible if “either Congress or two-thirds of the Senate has expressly or impliedly repealed the Senate’s original advice and consent” or otherwise withdrawn the United States from the treaty. Second, unilateral rejoining may not be possible if Congress passed legislation after the withdrawal in reliance on the withdrawal. For example, after the United States terminated the mutual defense treaty with Taiwan, subsequent legislation relied on normalized relations with China. Third, unilateral rejoining may not be possible if the president cannot, as Galbraith puts it, “rejoin it in a manner consistent with the Senate’s original resolution of advice and consent.” There may also be international law limitations to rejoining based on the original consent. For example, in the case of a bilateral agreement, the withdrawal of one party terminates the existence of the agreement. The Intermediate-Range Nuclear Forces Treaty, for example, was a bilateral treaty. Whether the United States can “rejoin” depends on whether the withdrawal is understood to have terminated the treaty or simply suspended it or portions of it.

The Senate’s position on the legality of unilateral withdrawals from Article II treaties may lend further support to the legality of unilateral re-joining of such treaties. If the withdrawal was arguably illegal, then the decision to reverse it may have particularly strong support. This will be more persuasive in cases where the decision to withdraw from the treaty entailed little or no consultation with the Senate, where it was inconsistent with congressional directives or instructions, or where Congress has expressly contested the withdrawal. For instance, prior to the Trump administration’s decision to withdraw from the Open Skies Treaty, Congress passed a federal law requiring the administration to determine that “withdrawing from the Open Skies Treaty is in the best interest of United States national security and that other parties to the Treaty have been consulted about the withdrawal.” The Trump administration did not comply with this requirement or engage in the “robust prior consultation with Congress” that members of Congress demanded.

3. Modify the rules for treaty consideration in Congress and then join or rejoin.

A longer-term option with potential broader benefits for treaties and international agreements would be to work with Congress on legislation creating new rules for considering international agreements in Congress. In the 1970s, Congress eased the process for making international trade agreements by giving the president so-called “fast track” negotiating authority, allowing the president to negotiate agreements and submit them to Congress for an up-or-down vote under special rules that prohibited any amendment, did not allow filibuster in the Senate, and placed strict limits on debate. This, or a similar construct, potentially could be established in other areas of law. (I made an argument for an expanded “fast track” for international law in a 2009 law review article.) However, as with Option 1, this is highly unlikely to be a practical solution in the near term, particularly given a new administration will likely want to act quickly on the international plane to signal its resolve in recommitting to an international rules-based order, shoring up its relationships with allies, and participating in global arrangements that seek to resolve pressing global problems.

This approach may be most natural for areas of law in which ex post congressional-executive agreements have been used in the past (for example, arms control), but it may be possible to use it in a number of other areas where Article II treaties have been more traditionally used as well. While this is legally defensible, it may run into political hurdles—namely congressional resistance to using an “expedited” process to approve agreements that have, in the past, been subject to advice and consent to ratification under Article II. As a “rejoining” option, agreements originally concluded as Article II treaties may run into political hurdles if they are proposed to be rejoined through the alternative process for ex post congressional-executive agreements, even though, as a legal matter, the two are arguably almost entirely interchangeable.

* * *

If Biden is elected president, he will have a great deal of work ahead of him to repair the damage done to the United States’ reputation in the international community. Part of that repair will entail rejoining the agreements from which Trump has systematically withdrawn. Doing so will require understanding where we stand and our options for moving forward.

This overview of the withdrawal decisions of the Trump administration and the challenge to repairing that damage also serves to highlight a deep asymmetry in U.S. international lawmaking: International agreements are often extremely difficult to make but easy for a president to break. This asymmetry is harmful to the United States’ long-term prospects as an effective actor on the international stage. While modifying the rules for treaty consideration in Congress is likely not practical as a short-term solution to the goal of repairing the damage done by the Trump administration, it may in the long term be the only way to fix what has become a broken U.S. international lawmaking system.

Image: Democratic presidential nominee, former U.S. Vice President Joe Biden and his running mate,  Senator Kamala Harris, sign required documents for receiving the Democratic nomination for President and Vice President, in Wilmington, Delaware, on August 14, 2020. Photo by MANDEL NGAN/AFP via Getty Images