[Editor’s note: This piece analyzes the newly updated War Powers Resolution Reporting Project of the Reiss Center on Law and Security, for which Bridgeman is author and lead researcher. It can be accessed at: https://warpowers.lawandsecurity.org/.]

With former President Donald Trump’s term in office over, it’s time to evaluate his war powers legacy and where it leaves the Biden administration as it begins to grapple with how and when to use force abroad in the absence of congressional authorization. The picture that emerges from Trump’s war powers reporting to Congress is one of an extraordinarily broad vision of the president’s authority to use force abroad without congressional authorization, and of a willingness to exploit loopholes in reporting requirements in a way that obscures information on the use of force from the public. This leaves President Biden and his lawyers the unenviable task of needing to decide whether to expend political capital to rein in claimed Article II authority — something the executive branch is often loath to do — and how to do it.

The War Powers Resolution of 1973 (WPR) is one of the primary laws on the books that creates the possibility of meaningful oversight of the President’s use of armed forces abroad. It requires the president to consult Congress before introducing armed forces into “hostilities” or “situations where imminent involvement in hostilities is clearly indicated by the circumstances,” and to notify Congress within 48 hours of having done so. These reports, known as “48-hour reports,” are also required when the president sends forces abroad “while equipped for combat” or “in numbers which substantially enlarge” existing combat-equipped deployments — the idea being to enable Congress to police the slippery slopes that can lead the nation to war. Reports must provide the legal basis for the president’s actions, the purpose of the deployment (or “circumstances necessitating the introduction”), and the “estimated scope and duration of the hostilities or involvement.”

The heart of the WPR was intended to be its termination provisions, which require the President to cease the use of armed forces within 60 days (extendable to 90 in some circumstances) of a “hostilities” report unless Congress has authorized their continued engagement, or whenever directed by concurrent resolution; but for a variety of reasons, these provisions have never been successfully used to force a withdrawal. The consultation requirements, too, have not empowered Congress to fulfill its constitutional role in deciding on matters of war and peace. This arguably makes the transparency-forcing reporting requirements the most practically useful aspect of the WPR today.

I launched the War Powers Resolution Reporting Project at NYU Law’s Reiss Center on Law and Security (RCLS) in February 2020 to track and analyze the war powers reporting practices of every president since the WPR’s enactment. The Project creates the first publicly accessible, searchable database of all unclassified 48-hour reports since the WPR’s enactment. It includes interactive graphics that allow users to explore the data and answer a range of questions about where, why, and how presidents are using U.S. armed forces abroad, compare reporting practices across presidencies, and view trends over time. Now, the database is updated to include all unclassified 48-hour reports filed during Trump’s presidency, providing the basis to assess where we stand as the Biden administration begins.

Trump’s War Powers Reporting Practice

So far as the public is aware, President Trump filed only six 48-hour reports during his four years in office — the exact same number as in Barack Obama’s and Ronald Reagan’s first terms, and in the ballpark of several others — if we include Trump’s classified report that was partially revealed to the public (described below). Three of Trump’s reports are relatively non-controversial, albeit sparse in detail. One involved staging combat-equipped forces in Gabon in January 2019 “to be in position to support the security of United States citizens, personnel, and diplomatic facilities in Kinshasa, Democratic Republic of the Congo” following tense elections there. A second reported the introduction of a “small number of combat-equipped” forces to Nigeria in November 2020 to conduct a successful hostage-rescue operation of a U.S. citizen. 

Deploying forces to protect U.S. nationals or property or to evacuate them if necessary are, when combined, the most common purposes for which presidents make WPR-reportable deployments. Since the WPR was enacted, every president except Reagan has reported operations to rescue or evacuate U.S. citizens, or missions to otherwise protect U.S. citizens or property, conducted under Art. II authority alone. And the U.S. Department of Justice (DOJ) has advised for more than half a century that “[T]he President’s authority has long been recognized as extending to the dispatch of armed forces outside of the United States, either on missions of good will or rescue, or for purposes of protecting American lives or property or American interests.”

A third Trump report falls into a different category: it notified Congress of the November 2019 build-up of additional U.S. forces and weapons systems in Saudi Arabia, purportedly in response to “hostile action by Iran and its proxy forces” in the region (a “substantial enlargement” in WPR terms). The stated purpose was “to assure our partners, deter further Iranian provocative behavior, and bolster regional defensive capabilities.” While the build up — and the related “maximum pressure” campaign against Iran — were highly controversial, the report is not extraordinary from a war powers perspective. The WPR was intended to inform Congress of significant increases in troop levels in potentially volatile situations, and that’s what occurred with this report.  

The other three reports, however, raise questions of whether there are any limiting principles left in the executive branch’s understanding of the president’s unilateral authority to use force abroad, and whether the WPR’s reporting requirements are sufficient, especially in the face of a presidency willing to exploit its loopholes.

Limitless Article II Authority

Seemingly occupying opposite ends of the policy spectrum, Trump’s overall war powers practice will simultaneously be remembered as much for precipitous and sometimes dubiously-motivated withdrawals of U.S. forces as for expansive — and sometimes lawless — claims of authority to take military action without congressional authorization even against foreign states. It is the latter set of practices that lie in the heartland of interbranch struggles on war powers, and for which the WPR was designed to ensure that Congress has a say. Trump’s strikes against the Syrian government in response to its chemical weapons use in 2017 and 2018 both fall into this category, as does the Soleimani strike discussed below. 

To be sure, the Trump administration was not the first, and will almost surely not be the last, to claim broad legal authority for military action without congressional authorization. The analysis reflected in the database shows that roughly a third of the 48-hour reports to date cover deployments of forces into hostilities (or imminent hostilities) on Art. II authority alone. But more remarkably, half of those reports (17 of the 106 in the database) are for purposes that lie beyond the long-recognized core of the president’s unilateral authority to use force abroad: defending the United States against sudden attack or defending U.S. nationals or property in situations of peril. The 17 reports that stretch the boundaries of Art. II authority span the administrations of Presidents Reagan, H.W. Bush, Clinton, Obama, and now Trump.

Notably, in most of the situations in which presidents claimed unilateral authority for these more controversial missions, other tempering factors were present — the associated reports often described an international legal basis for the action, for example, even though this is not necessary (or sufficient) to satisfy the terms of the WPR. Almost all of the operations in these 17 reports were undertaken pursuant to UN Security Council authorization or with the consent of the state in which force was being used. In addition, almost all of them were undertaken with coalitions: as a policy matter, the executive branch sought legitimacy in the strength of the coalition (when undertaken with NATO, for example, in the former Yugoslavia and in Libya) and, in many but certainly not all cases, the humanitarian nature of the mission.  

Trump’s strikes against the Assad regime in Syria (again, along with the Soleimani strike) arguably represent some of the farthest reaches of claimed unilateral presidential authority to use force abroad (at least since the George W. Bush administration). DOJ’s Office of Legal Counsel (OLC) opinion finalized a month after the 2018 strike claims extraordinarily broad constitutional authority to use force absent congressional authorization.The two-part test that OLC has developed over several decades to determine whether the president may use force unilaterally requires assessing whether the use of force: (1) would be in the “national interest;” and (2) “would not rise to the level of war in the constitutional sense.” Part 1, according to the opinion itself, is “a question more of policy than of law” and OLC’s purpose in including the inquiry is “not to evaluate” the actual interests at stake by some constitutional standard but to “set forth the justifications for the President’s use of military force and to situate those interests within a framework of prior precedents.” It is, as a legal matter, essentially superfluous. Part 2, intended to preserve Congress’ constitutional authority in bringing the nation to war, has also been stretched so far that short of a ground war with the likelihood of substantial U.S. casualties, Congress’s constitutional role can safely be ignored.

DOJ’s opinions for Trump, of course, expand upon a line of opinions provided for previous presidents seeking to use force without congressional authorization in situations beyond self-defense from imminent attack. But Trump’s two Syria operations lacked some of the tempering factors present in most earlier cases. For example, his 48-hour WPR reports said nothing of a purported international law basis for the strikes – and, while that is in part because Trump chose not to report the international legal underpinnings in any of his WPR reports, it also reflects the fact that the strikes had no international law basis, but in fact violated the bedrock prohibition against the use of force enshrined in the UN Charter and customary international law. And while the 2018 strikes were undertaken with the UK and France, the 2017 strikes were conducted by the United States alone. In addition, while portrayed by the Trump administration as humanitarian in nature, they arguably did not actually protect Syrian civilians from harm. 

It’s important to recognize that Obama had threatened to take a very similar action in 2013, on similar grounds, and claimed to “possess the authority to order military strikes” unilaterally. But while it was his “judgment as Commander-in-Chief” that strikes against Assad were, on balance, appropriate, he told the public that he would not take the strikes unilaterally. In a public speech he explained: 

But I’m also the President of the world’s oldest constitutional democracy…. I believed it was right, in the absence of a direct or imminent threat to our security, to take this debate to Congress. I believe our democracy is stronger when the President acts with the support of Congress. And I believe that America acts more effectively abroad when we stand together. 

There is much to unpack here — from the implication that a violation of international law can be remedied by another violation of international law to the recognition that Assad did not present a direct or an imminent threat to the security of the United States. From an interbranch war powers perspective, however, what is striking is Obama’s acknowledgement that when the president is not acting in the defense of the United States, it is “right” in our constitutional democracy for Congress to decide whether or not to authorize the use of force. In a sense, he was having his Art. II cake and eating it too — claiming authority to act unilaterally (which he did, for example, in Libya), but also supporting the (in my view correct) position that Congress should authorize military force against another nation state when the president is not acting quickly to defend the United States from an imminent threat of armed attack. This of course implies the view (which is in my view incorrect) that going to Congress in such a situation is the “right” and “stronger” choice, but ultimately a discretionary one. 

In 2013, Congress did not authorize the use of force against Assad, and Obama did not take the strikes he had advocated. In 2017 (and 2018), Trump did not go to Congress, and he did strike. 

Classified Reporting

On Jan. 4, 2020, Trump filed a 48-hour report notifying Congress of a U.S. drone strike that killed Iranian General Qassem Soleimani (and Iraqi military personnel) in Baghdad, Iraq, on Jan. 2, 2020. The report was submitted only in classified form (and thus is not included in the Project database), although unclassified portions were subsequently made public by lawmakers without authorization of the executive branch. 

It remains unclear whether the three (or more) paragraphs of the 48-hour report that were not made public disclose more information about the Soleimani strike, or whether the letter also served to notify Congress of additional strikes, such as the reported “classified mission” that tried but failed to target a different Iranian military official (Abdul Reza Shahlai) on the same day in Yemen. Notably, the Department of Defense publicly acknowledged the United States conducted the Soleimani attack on the day it occurred in an official statement. And some of the statutorily required information in any 48-hour report, such as the domestic legal authority under which the Soleimani strike was carried out, does not appear in the unclassified paragraphs of the report, raising the question as to whether it was considered classified because it referenced other military operations that remained classified (for example, it may have used the plural in stating “I directed these actions pursuant to my constitutional authority,” or a similar formulation). 

Leaving to one side the at best dubious legality of the Soleimani strike under both domestic and international law, the notable issue from a war powers reporting perspective is that, while notifying Congress of the hostilities only in classified form may was non-transparent, and potentially an abuse of classification authority (depending on what is in the three or more blacked out paragraphs), doing so did not flout the requirements of the War Powers Resolution itself. This is because the WPR does not require that 48-hour reports be submitted in unclassified form, but rather remains silent on classification of reporting.

Even if the 48-hour report had not been disclosed, at least some aspects of the Trump administration’s legal justification for the strikes were made public by virtue of additional domestic and international legal obligations to report the strikes to Congress and the UN Security Council (pursuant to section 1264 of the FY2018 National Defense Authorization Act (NDAA) and Art. 51 of the UN Charter, respectively). But these reports fulfill different functions than 48-hour WPR reports. Section 1264 reports are an important innovation that fill some gaps in the WPR reporting framework (in requiring more detailed information about the legal, factual, and policy justifications for a range of executive branch actions), but are only required to be submitted 30 days after the reportable event, do not require reporting on what happens next, and can also be partially classified. Art. 51 notifications, while crucial, do not fulfill the 48-hour report’s function of providing the domestic legal basis of the action. They are also sometimes filed late, as was the case with the Soleimani strike, and do not necessarily create transparency even among UN member states (as Pablo Arrocha Olabuenaga has argued here and here). And perhaps most important, only 48-hour reports start the WPR’s 60-day clock — once that clock runs out, U.S. forces must be withdrawn from ongoing hostilities unless authorized by Congress. 

Speaker Pelosi called the classification of Trump’s Soleimani strike report “highly unusual.” But this 48-hour report may not have been the first to be classified. In his and past administrations, some periodic WPR reports — required to be filed at least every six months to update Congress on the status, scope, and duration of reported deployments — mention a classified annex, raising the prospect of classified 48-hour reporting during the preceding six-month period. But the failure to file an unclassified report that would be made available to Congress and the public in such a high-profile attack as the Soleimani strike, for which the United States immediately claimed responsibility, with great attendant risks of escalation to all-out war with a nation-state, and no prior authorization from Congress, shines a spotlight on this reporting loophole. 

Questions for the Biden Administration

As a candidate, Biden committed that “the use of force should be our last resort, not our first—used only to defend our vital interests, when the objective is clear and achievable, and with the informed consent of the American people.” This is a policy statement, not a legal standard. But several of the limiting elements it contains — in particular using force only to defend vital interests, and in such cases only with the informed consent of the American people (presumably via their representatives in Congress) — would constrict unilateral uses of force to arguably much narrower circumstances than current OLC doctrine permits. This depends, however, on what content the new administration gives those somewhat ambiguous terms and how far it is willing to go in turning these political commitments into meaningful constraints on what has become nearly unfettered executive branch authority. 

One way to at least halt, if not dial back, claims of unilateral presidential power is simply to not use force abroad beyond the core of Art. II authority — that is, roughly speaking, responding to or preventing armed attacks, and defending U.S. nationals in peril — absent congressional authorization. With Biden’s long and distinguished history in the Senate, including as Chair and Ranking Member of the Senate Foreign Relations Committee, he understands the institutional prerogatives of Congress. 

Indeed, in 1988, then-Senator Biden, who had recently chaired a Senate Special Subcommittee on War Powers, advocated for a “joint decision” model of war powers. He argued that the “President draws his independent authority not from some robust concept of the President as an all-knowing and nearly omnipotent Commander-in-Chief,” but from a limited “responsibility to protect the nation and its citizens from immediate threats.” Thus, 

presidential power to use force in the absence of statutory authorization derives from the concept of emergency: the need to repel an attack on the United States or its forces, to forestall an imminent attack, or to rescue United States citizens whose lives are imperiled. Conversely, any policy involving a sustained use of force must derive from an affirmative decision of the entire government, including Congress.

But this is easier said than done. It is very likely that on Biden’s watch there will be some humanitarian catastrophe, some partner state asking for help, or some other unforeseen circumstance that leads to a desire to use military force beyond core notions of self-defense, and without prior authorization from Congress. And if the Biden administration makes good on its promise to end the forever wars, it will hopefully be relying less on the stale statutory force authorizations passed by Congress in 2001 and 2002 for conflicts in Afghanistan and Iraq respectively but now relied on by the executive as the legal authority for counterterrorism operations around the globe. This, in turn, will likely create more pressure to rely on Art. II authority when a use of force is deemed necessary. In such a case, Biden should commit to not only upholding the letter of the WPR, and to ensuring unclassified and thorough reporting that provides Congress the ability to exercise meaningful oversight, but most important, to seeking authorization from Congress for uses of force that fall outside “the concept of emergency” he so aptly described as a Senator. 

And although this runs counter to how executive branch lawyers are generally expected to operate, Biden and his senior advisors should also commit to asking his OLC to provide not the best pathway to yes when interpreting the scope of his war powers under Art. II, but the best view of the law, without undue or excessively narrow focus merely on executive branch precedent. 

Biden’s OLC should, in turn, commit to finally articulating limiting principles on its standards for when the president may use force abroad without congressional authorization, rather than simply accreting evermore examples of what the Constitution purportedly permits. What is not in the “national interest”? Are there any criteria for identifying which national interests are sufficient to support unilateral presidential uses of force? And is the “national interest” even the correct standard for a legal test as opposed to a policy lens for when a president should use force unilaterally? In modern armed conflict, must there be boots on the ground and prolonged engagement with high risk of U.S. casualties for a use of force to constitute war “in the constitutional sense”? More fundamentally, should the executive’s interpretation be based more squarely on the underlying purpose of the allocation of war powers in the Constitution? 

Finally, the Biden administration should embrace wholesale reform of the WPR framework, just as Senator Biden did decades ago. As he recognized then, “the [War Powers] Resolution contains readily identifiable flaws,” but “they are correctable.”

From adding real teeth back into the termination requirement and shortening the 60-day clock, to defining key terms, to increasing the quality of reporting, there are plenty of serious proposals on the table. Amidst growing bipartisan consensus on the need to rebalance the scales of war powers between the president and Congress once again, and with a president in office who understands the stakes from both branches, now is the time to act.