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In the Absence of Legal Authority: U.S. Airstrikes in Syria

By: Katherine Youssouf

On Friday night, April 13th, at the order of the President, the United States launched a series of precision airstrikes against three Syrian military targets. These targets were believed to house, or contribute to the research and development of chemical weapons under the regime of Bashar al-Assad. The airstrikes were the result of a collaborative operation with the governments of the United Kingdom and France, which involved the use of 105 Tomahawk,  Storm Shadow/SCALP EG, and air-to-surface standoff missiles launched from the air, eastern Mediterranean Sea, Persian Gulf, and the Red Sea. President Trump stated in a televised address to the American people on Friday evening that the strikes were launched against the Syrian government in response to the April 7th chemical weapons attack on rebel-held Douma. That attack took the lives of more than 40 people. By Sunday evening, an estimated 500 people, including young children, had flooded Syrian health facilities, reporting symptoms of burning eyes, breathing challenges, and other symptoms that the World Health Organization states are consistent with exposure to toxic chemicals.

Chemical weapons—deadly weapons of mass destruction containing various toxins or poisons—are strictly prohibited under international law. This prohibition is codified in the Chemical Weapons Convention, the Statute of the International Criminal Court, the Hague Declaration concerning Asphyxiating Gases, and the Geneva Gas Protocol. Further prohibitions can be found in numerous military manuals and the case law of several national courts. Still, none of these instruments have restrained the attacks committed by the Assad regime. Since 2013, there have been 34 cases of chemical attacks by the Syrian government, most of which have involved the use chlorine or sarin. These cases have been investigated and confirmed by the Independent International Commission of the Inquiry on the Syrian Arab Republic, an independent body established by the United Nations Human Rights Council to investigate human rights violations in Syria.

In April of last year, a chemical weapons attack committed by the Assad regime took the lives of 70 people. In response, the Trump Administration launched a military strike consisting of 59 Tomahawk cruise missiles against a Syrian airbase. Pentagon officials have stated that both strikes launched by the U.S. were designed to deter the Assad regime’s continued use of chemical weapons. The Trump Administration justifies its actions on two grounds: first, the Administration believes Assad’s chemical weapons attacks are the direct result of the Obama Administration’s failure to uphold its red line after the attack in Ghouta in 2013; second, the Administration believes that one-off strikes are sufficient response to deter future attacks. However, research conducted by the Violations Documentation Center, a Swiss independent monitoring group, suggests that both arguments are inaccurate.

Both former President Obama and President Trump have ordered airstrikes on Syria. However, these strikes are distinctly different. The attacks under the Obama Administration were launched just as the U.S. was beginning its military campaign against ISIS in Iraq and Syria. These airstrikes led to a steady stream of attacks authorized by the Authorization for the Use of Military Force (AUMF), a law passed by Congress in the wake of 9/11. The AUMF authorizes the President  “to use all necessary and appropriate force against those nations, organizations, or person he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001.” The 2001 AUMF was necessarily drafted in broad terms, but its application is not unlimited.

Consistent with Section 8(a)(1) of the War Powers Resolution of 1973, requiring that the President consult with Congress before introducing U.S. armed forces into hostilities, and Article I, Section 8 of the U.S. Constitution, which gives Congress the power to make declarations of war, the 2001 AUMF provides the President, as Commander in Chief, with specific Congressional authorization to use force only against the attackers of 9/11 and their associated forces. This use of force must fall within the meaning of Section 5(b) of the War Powers Resolution. In 2001, the AUMF provided former President Bush with the authorization to take military action against Al-Qaeda and its affiliates. Under the Obama Administration, the scope of the 2001 AUMF was expanded to include successor organizations, like ISIS.

During Guantanamo habeas litigation, the Obama Administration filed a memo outlining the President’s interpretation of the 2001 AUMF. The memo explained that the statute authorized the detention of “persons who were part of, or substantially supported, Taliban or [Al-Qaeda] forces or associated forces…engaged in hostilities against the United States or its coalition partners…..” This interpretation was upheld by the D.C. Circuit and the National Defense Authorization Act for Fiscal Year 2012 and continues to be employed today.

As an offshoot of Al-Qaeda, ISIS falls within the ambit of the “associated forces” extension of the AUMF, and thus provides the President with Congressional authorization to use force against ISIS in Syria. This authorization is not, however, applicable to the airstrikes against the Syrian government launched under President Trump.  

No one disputes the level of cruelty that comes from the use of chemical weapons by the Assad regime. But no reading or interpretation of the language of the 2001 AUMF provides the President with Congressional authorization to use force against it. The Trump Administration cannot use the 2001 AUMF as statutory authorization for attacks against the Syrian government. Congress has not enacted an Authorization to Use Military Force in Syria, and without statutory authorization—and a direct threat to the United States—President Trump’s use of U.S. armed forces is outside the scope of his authority and in violation of U.S. domestic law. Even if the Administration attempts to rely on the President’s Article II powers as Commander in Chief, the extent of a President’s authority to use military force in the absence of Congressional authorization continues to be vigorously contested. This is why, on April 13th, a bipartisan coalition of Congressional members composed a letter to the President urging him to consult and receive authorization from Congress, as is prescribed by the War Powers Resolution, before ordering additional use U.S. military forces in Syria.

As a matter of international law, President Trump also lacks clear authority for the strikes against Syria. Under Article 2(4) of the UN Charter, the U.S. is prohibited from the use of force unless it has express authorization from the Security Council or it is exercising its right to individual or collective self-defense under Article 51. Currently, there is no Security Council authorization for States’ force against Syria, and the U.S. cannot claim self-defense without being the victim of an armed attack. To assert a collective self-defense justification, another “victim state” would have had to declare itself the victim of Assad’s attack and request military aid from the U.S. in response. At present, the facts do not demonstrate that any declaration warranting a response was made. Authorization by the Security Council and the right to self-defense are the only two exceptions applicable to the U.S. under international law. The U.S. has never recognized a right of humanitarian intervention under international law, and thus cannot invoke it as an exception to Article 2(4) at this time. Therefore, though Assad’s chemical weapons attacks are undeniably unlawful, the Trump Administration’s airstrikes are as well.

Without justification in domestic or international law, future U.S. airstrikes on the Syrian government will occur without legal grounding. Only time will tell how these strikes will be perceived by the international community, and how Syrian allies, like Russia and Iran, will retaliate. At the domestic level, the continued conflict between U.S. strikes and U.S. law places pressure on Congress to pass specific statutory authorization for the use of military force in Syria, lest these U.S. airstrikes will continue in the absence of legal grounds.


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