On December 19, 2018, President Trump ordered the withdrawal of all American forces from Syria. While a total withdrawal has still not been achieved, this move entails consequences for the United States’ allies and a shift in the balance of power in the country. It also provides a valuable lesson for countries around the world in American foreign policy. While the foreign policy ramifications of leaving local allies in the lurch will stain the U.S.’ reputation, the Trump Administration is constrained by the domestic foreign affairs legal framework. Domestic law binds countries, and it is a necessary factor to consider in diplomacy. If countries are to predict how the United States military might act in the future, it is vital to understand these domestic legal constraints.
Status Quo in Syria
U.S. forces entered Syria back in September 2014 under the pretext of stopping the burgeoning pseudo-terrorist Islamic State in Iraq and Syria (ISIS). At its height in 2015, ISIS, from its capital at Raqqa, controlled nearly half of Syria and a significant part of northern Iraq, including the regional capital of Mosul.
Since mid-2015, a coalition of forces gradually pushed back ISIS so that the terrorist network lost all of its major cities in 2017. While a few pockets of resistance fighters remain, and a shadow state exists online that still commands terrorist attacks around the world, ISIS as a territorial entity is all but dead. Iranian President Hassan Rouhani and Russian President Vladimir Putin both declared victory over ISIS in November 2017. Along with his announcement of a Syrian withdrawal, President Trump also told the press that ISIS was defeated.
The Law Binds
It is the fall of ISIS that legally prevents the American military from remaining in Syria. Among other considerations, the Trump Administration no doubt looked at its own domestic authorization to remain in Syria. Under the 1973 War Powers Resolution, the President’s power to enter into hostilities is limited and involves a number of Congressional reporting requirements as well as time limits on how long U.S. forces can remain committed abroad. The War Powers Resolution is a powerful constraint on the United States’ ability to engage in military action abroad.
Congress passed the War Powers Resolution in 1973 following a series of unpopular American military operations. The United States was wrapping up its long, costly, and ultimately futile involvement in the Vietnam War that year, following strong public opposition to the war. At the same time, the United States had also engaged in military operations in Cambodia just a few years before. The War Powers Resolution was largely a response to the perceived abuse of power by the Johnson and Nixon Administrations. Despite President Richard Nixon’s veto of the War Powers Resolution, the U.S. Congress overturned Nixon’s veto and passed the law, which has remained a core part of how the United States legally wages war.
One exception to the War Powers Resolution is if Congress has provided authorization to act. The 2001 Authorization for Use of Military Force (AUMF) allowed the United States to fight anyone who was a part of or substantially supported the groups that carried out the 9/11 terrorist attacks, namely Al-Qaeda and the Taliban. As an offshoot of Al-Qaeda, ISIS fell under the scope of the AUMF. However, by 2018, with the declared victory over ISIS, this justification was gone.
The Obama Administration Office of Legal Counsel (OLC) developed a legal framework in 2011 for engaging in foreign military operations without Congressional approval if this engagement was for an American “national interest” and the operation did not constitute war, meaning an operation that was limited in nature, scope, and duration. Supporting allies was upheld as a national interest in a 2014 OLC opinion in which the Obama Administration justified U.S. activities against ISIS to support the United States’ ally, Iraq. However, the perceived risk of rising to the level of war then was low. Today, any further military support for the Kurdish Syrian Democratic Forces in Syria would risk a wider war in the region, potentially with serious military powerhouses Russia, Iran, and Turkey. While supporting an ally might be in Washington’s national interests, a wider war in the region would certainly not be.
Even if the Trump Administration felt that it could justify further operations in Syria under the 2011 OLC framework, it would still be subject to the War Powers Resolution limitations, including a 60-day limit on the campaign. The Obama Administration legal advisor for the State Department, Harold Koh, developed a framework which posited that if an operation is limited and has a low risk to armed forces and of escalating, it does not qualify as hostilities and is therefore not subject to the War Powers Resolution restrictions. Considering the complicated situation in Syria and the involvement of numerous powerful foreign nations, it would be hard for U.S. leadership to argue that remaining in Syria in 2019 would not rise to the level of hostilities and the potential for a greater war.
Due to these risks, the Trump Administration could not use the 2011 OLC or Koh frameworks to authorize U.S. forces remaining in Syria. Legal scholars and the media have previously criticized U.S. involvement in Syria for infringing the War Powers Resolution, but this approach has not really been used to analyze the announced withdrawal. Unable to use the Obama era exceptions and without specific Congressional authorization, the War Powers Resolution prevents the Trump Administration from engaging in military operations in Syria by requiring justifications to Congress and capping any further operations at 60 days. Although U.S. foreign affairs law is murky, the Trump Administration, by admitting that ISIS is defeated, is left without legal authorization to maintain an operation in Syria.
Lesson for Foreign Affairs
While the American withdrawal from Syria is a catastrophe for American allies in the country, it is a teachable moment. The image of the ever-interfering American military is a powerful one across the globe. However, the War Powers Resolution is a serious constraint on swift, unilateral military action by the president.
Ultimately, understanding the War Powers Resolution and the workarounds created by the Obama Administration would provide a powerful tool for predicting if, where, and how the American military might act. While formal alliances would count as a national interest, the risk of escalation and harm to American troops must be low for the president to act unilaterally. This is how the United States could bomb Libya, which was not entangled with foreign powers, but now needs to withdraw from Syria. It might have even been in the strategic interests of major foreign players in Syria, namely Turkey, Russia, and Iran, to combine forces to crush ISIS, removing the casus belli for the American presence there.
This set of constrains is not new, but it is a consideration that is overlooked time and again in evaluating how the United States may act in the foreign affairs arena. It is a valuable lesson from the American withdrawal in Syria.