How Congress Abdicated War Powers, Paving the Way for Trump’s Iran Conflict

President Donald Trump and his administration have long claimed that he seeks a more restrained foreign policy. Before the 2024 presidential election, his running mate, J.D. Vance, labeled Trump the "candidate of peace." Trump broke with Republican orthodoxy during a 2016 presidential debate, calling the Iraq War "a big, fat mistake." Yet a decade later, his administration is embroiled in a conflict that closely resembles the one he once condemned.

On February 28, 2024, the U.S. and Israel launched strikes against multiple targets in Iran, killing Ayatollah Ali Khamenei, the country’s supreme leader. Since then, Iran has retaliated by striking several U.S. diplomatic offices and military facilities in the Middle East, while the U.S. has targeted missile and oil sites across Iran. As of mid-April 2024, 13 American service members had died in the conflict, which showed no signs of abating. Reports indicated the U.S. was considering larger troop deployments to the region, and at press time, Trump had not ruled out deploying American ground forces.

The Trump administration offered shifting justifications for its military actions in Iran, none of which were authorized by Congress. As Reason’s Matthew Petti noted in March 2024, officials cited multiple, often contradictory reasons: to preempt a potential Iranian attack (which other officials claimed "wasn’t real"), to join an Israeli strike that would occur "with or without the United States," to exploit a fleeting opportunity to kill Iranian leadership, or to punish Iran for failing to meet U.S. demands on nuclear concessions.

Congress’s Abdication of War Powers

The U.S. Constitution grants Congress the sole authority to declare war. Yet constitutional control over warmaking has eroded to the point where presidents no longer feel compelled to present a coherent case for military action to lawmakers. Congress, for its part, has systematically weakened its own role in matters of war.

Congress last voted to declare war in 1942, authorizing action against Bulgaria, Hungary, and Romania during World War II. Since then, U.S. military engagements have been justified through Authorization for the Use of Military Force (AUMF) resolutions or unilateral presidential decisions. AUMFs are joint resolutions that grant the president broad discretion to deploy military force, often without clear limits or sunset provisions. These resolutions can remain in effect for decades and are frequently invoked to justify conflicts far beyond their original intent.

The 2001 AUMF, which authorized the president to use "all necessary and appropriate force" against any entity involved in the September 11 attacks, had been cited to justify counterterrorism operations in 22 countries as of 2020, according to Brown University’s Costs of War Project.

Presidential Overreach and Congressional Inaction

Presidents have additional tools to bypass congressional oversight. The 1973 War Powers Resolution was designed to curb executive warmaking by requiring presidential consultation with Congress. However, the law has proven ineffective, as presidents have repeatedly ignored or circumvented its requirements. For example, President Barack Obama claimed the War Powers Resolution did not apply to his bombing campaigns in Libya in 2011, setting a precedent for future administrations to act unilaterally.

Political scientists like Sarah Burns of the Rochester Institute of Technology argue that the War Powers Resolution "opens the door for presidents to engage in smaller-scale or short operations" without meaningful congressional oversight. This loophole has enabled decades of executive-led military engagements, from drone strikes in Yemen to the 2020 assassination of Iranian General Qasem Soleimani—an action Trump later praised as a "beautiful" operation.

Critics argue that Congress’s failure to assert its constitutional authority has emboldened presidential overreach. Without a renewed commitment to oversight, future presidents—regardless of party—may continue to wage war without congressional approval, further eroding the separation of powers enshrined in the Constitution.