Foreign Policy

Today Marks 80 Years Since Congress Last Bothered To Declare a War

Presidents once treated congressional authorization as a requirement for the U.S. to enter conflicts. What went wrong?


Congress issued its last official declaration of war 80 years ago today, marking the last time the president deferred to the war-making process outlined by Article I, Section 8 of the Constitution before entering a conflict. Since 1942, when it authorized the use of military force against Hungary, Bulgaria, and Rumania in World War II, Congress has abdicated its proper role in American war making. Blank-check authorizations now shield the president from domestic accountability for his use of military force.

The Constitution gives Congress the sole authority to declare war. Since the presidency of George Washington, it's invoked that power 11 times to fight nations in five distinct conflicts—the War of 1812, the Mexican-American War, the Spanish-American War, World War I, and World War II. In each case, the president had to first request congressional authorization either in writing or in person. He would explain his justification for why the U.S. should enter the conflict at hand. Congress would then put it to a vote—majority support was required, but most declarations were passed unanimously or near-unanimously—and pass a declaration of war in the form of a bill or joint resolution.

The Founding Fathers were rightly skeptical of an executive with an unbridled capacity to wage war. "Nations in general will make war whenever they have a prospect of getting anything by it," John Jay wrote in Federalist No. 4. "Absolute monarchs will often make war when their nations are to get nothing by it, but for purposes and objects merely personal, such as thirst for military glory, revenge for personal affronts, ambition, or private compacts to aggrandize or support their particular families or partisans." Such factors could motivate the executive "to engage in wars not sanctified by justice or the voice and interests of his people."

Presidents once treated congressional approval as a necessary condition—a legal requirement—for the U.S. to enter hostilities. But this constitutionally ordained process has given way to more recent executives relying on a hodgepodge mix of authorizations and external validation to justify the use of military force without consulting Congress.

Some presidents have claimed justification through international organizations in order to enter conflicts. President Bill Clinton looked to the United Nations Security Council for approval to use military force in Haiti and didn't seek the support of Congress. President Barack Obama didn't secure authorization from Congress before U.S forces began to enforce a no-fly zone over Libya, which involved the use of military force over the course of seven months. According to the National Constitution Center, modern conflicts that lacked congressional approval include President Harry Truman's entry into Korea; President Ronald Reagan's military operations in Libya, Grenada, and Lebanon; and President George H.W. Bush's invasion of Panama.

But far from being unjustly overridden, Congress has helped weaken its own role in war making. It's passed several Authorizations for the Use of Military Force (AUMFs) designed to give the president broad discretion in specific conflicts or against clearly defined threats. However, these authorizations have permitted the president to use U.S. military force in dubious ways. The 2001 AUMF may have been drafted to let the president "use all necessary and appropriate force" against the parties behind the September 11 attacks, but presidents have capitalized on the authorization's overly broad phrasing to justify 41 operations in 19 countries. While the president once had to convince members of Congress to support American entry into conflicts, lawmakers themselves have diluted their say by signing away so much power.

Debate abounds over presidential discretion in many realms of conflict. Scholars and commentators question what falls under the president's purview and what is only permissible after a congressional declaration of war: defensive strikes, actions against nonstate actors, engagement in low-level hostilities, deployment of peacekeepers, enforcement of no-fly zones, and on and on. Regardless of the nuances, it's undeniable that the mechanisms behind American war making have changed enormously in the past century.

With that, it's worth remembering that the president's current war powers come not just at the expense of Congress but the American people as well. Bringing lawmakers into the fold of war authorization ensures that their constituents' approval or disapproval of a conflict is voiced, at least in theory. It's now effectively optional for a president to make his case for force and face the political costs that follow. Modern American engagement in hostilities is not representative of a popular mandate but rather presidential lawyering and decision making carried out beyond public view.