Fight over Trump’s Iran war powers comes after a long stretch of Congress yielding to presidents

Congress and White House Clash Over War Powers as Trump Expands Military Actions

Congress is once again challenging President Donald Trump’s military authority, this time regarding operations in the Middle East, following earlier debates about interventions in Latin America.

The Republican-controlled House is set to vote Thursday on a measure that would potentially limit Trump’s warmaking powers, after the Senate recently rejected a similar Democratic proposal related to U.S. involvement in the Israeli-Iranian conflict.

Trump has repeatedly asserted broad, even unlimited authority over U.S. military forces during his second term. His administration has authorized boat strikes near Venezuela, established a naval blockade, and approved a military operation aimed at deposing Venezuelan President Nicolás Maduro—actions that international law experts consider possible acts of war. More recently, Trump launched extensive bombing campaigns in Iran that have resulted in six U.S. service member deaths.

“The Constitution gives war powers to two different branches of government,” said Peter Mansoor, military historian, Ohio State University professor, and retired U.S. Army colonel. “The pendulum has swung towards the executive,” he noted, adding that “the framers meant for Congress to be the most powerful branch.”

The Constitution’s division of war powers is clear in theory but has become increasingly blurred in practice. Article I grants Congress the power “to declare war,” while Article II designates the president as “commander in chief of the Army and Navy.” Congress also controls military funding, providing another potential check on executive action.

Despite these constitutional provisions, Congress has not formally declared war since World War II. Nevertheless, American troops have fought and died in numerous conflicts since 1945, including Korea, Vietnam, Iraq and Afghanistan—all without official war declarations.

During Senate debates on Venezuela, Senator Rand Paul (R-Ky.) criticized what he called an “elaborate song and dance” around presidential military action, saying it’s “an absurdity” to claim Trump’s actions were anything but waging war. Senator Tim Kaine (D-Va.), who sponsored both Venezuela and Iran war powers resolutions, argued his measures would prevent presidential “end-runs around the Constitution.”

The shift toward expanded presidential war powers began notably with the Korean War in 1950. President Harry Truman deployed U.S. troops without congressional approval, citing United Nations authorization instead. Congress later passed the Defense Production Act, effectively endorsing Truman’s decision after the fact.

The Vietnam conflict further demonstrated the erosion of congressional war authority. While President Lyndon Johnson secured the Gulf of Tonkin Resolution in 1964, providing broad authorization for military action, Congress later repealed it in 1971. Yet President Richard Nixon continued operations regardless, illustrating the president’s expanded power.

“Congress approves and supports the determination of the President, as Commander-in-Chief, to repel any armed attack against the forces of the United States and to prevent further aggression,” stated the 1964 resolution, language that granted sweeping authority.

In response to these expansions of executive power, Congress passed the War Powers Resolution in 1973, requiring presidents to notify lawmakers of military deployments and allowing Congress to set parameters for military action. This legislation provided the framework for this year’s failed resolutions regarding Venezuela and Iran.

However, subsequent presidents have generally found ways to work around these constraints. Ronald Reagan sent troops to Lebanon in 1982 without citing the War Powers Resolution. George H.W. Bush asked Congress for “support” rather than “authorization” for the Gulf War. Bill Clinton deployed forces to multiple countries without explicit congressional approval.

After the September 11, 2001 attacks, George W. Bush received near-unanimous congressional support for a joint resolution authorizing action against terrorists, though it named no specific country. This authorization, which had no effective end date, was later used to justify military operations worldwide. Bush did return to Congress in 2002 to seek specific authorization for action against Iraq.

These authorizations remained in effect through Barack Obama’s presidency, Donald Trump’s first term, and into Joe Biden’s administration, enabling what Mansoor calls “forever wars.” Biden ultimately withdrew U.S. troops from Afghanistan, ending America’s longest undeclared war.

As Trump’s administration continues to expand military operations globally, the constitutional tension between presidential authority and congressional oversight remains unresolved, with each branch claiming primacy in determining when and how American military force can be deployed.