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War Powers


WAR POWERS. Since the United States was created, Congress and the president have been in conflict over which branch of government has the power to make war. Though the Constitution gives the balance of war power to the legislative branch, the executive branch has steadily enlarged its authority for more than a century.

In 1787, the framers of the Constitution were eager to reject the English precedent granting the king authority over most matters of foreign policy, including military decisions. Consequently, they gave to Congress the key powers of declaring war and raising and regulating the various armed forces. The president received the strictly defensive, emergency power to "repel sudden attacks" and the title Commander in Chief, which entailed leading armies only after Congress had formed them and committed America to war.

In the decades after the Constitution was ratified, presidents mostly deferred to the legislative branch in military affairs. For example, even though George Washington's campaigns against various Indian tribes were considered defensive, Congress nevertheless repeatedly authorized his use of force on the frontier. Though James Madison asked Congress to declare what became known as the War of 1812, he did not take action for several weeks while the House and Senate debated.

President James K. Polk was the first executive to assume significant war power for himself, during the Mexican-American War (1846–1848). After negotiations with Mexico to purchase parts of California and New Mexico failed, Polk opted to take the land by force. He sent American troops to disputed territory along the Texas-Mexico border and later told Congress that America had been invaded and that "war exists." Though Congress eventually made a declaration, it censured Polk two years later on the grounds that the war had been "unnecessarily and unconstitutionally begun."

In the early twentieth century, presidents began to conceive of their defensive war powers more broadly, as a mandate to protect American interests wherever they were threatened. The new rationale served the United States' increasingly imperial foreign policy by justifying a series of far-flung military commitments. In 1903, for example, Theodore Roosevelt was having difficulty buying the rights to what would become the Panama Canal Zone from Colombia, which then controlled Panama. To make the transaction easier, he both financed and provided troop support for a Panamanian revolution, knowing that a nominally independent but quiescent Panama would grant cheap access to the canal zone. Woodrow Wilson sent troops to Mexico (1914), Haiti (1915), and the Dominican Republic (1916) out of a general determination to dominate the hemisphere and export American values. Though Congress gave subsequent approval to some of these invasions, they were initiated by presidents claiming expansive, unprecedented war power.

In 1936, the Supreme Court's decision in United States v. Curtiss-Wright Corporation helped legitimize growing conceptions of executive authority. The Court ruled that Congress could give the president more discretion in foreign affairs than would be appropriate in domestic matters. Moreover, it gave the president the authority to make diplomatic policy independently on the grounds that the president is the "sole organ of the federal government in the field of international relations." The judiciary has since cited Curtiss-Wright in numerous decisions upholding presidential war power.

Since World War II, presidents have made several large-scale military commitments and many smaller ones without congressional authorization. They tend to cite their own authority as commander in chief and often claim to be acting pursuant to United Nations resolutions or mutual treaties (such as NATO or SEATO). Harry Truman cited two UN Security Council resolutions to justify involvement in the Korean War (1950–1953). He failed to notify Congress until after he committed troops, and his administration chose not to seek congressional support. Several days after Truman sent forces to Korea, he claimed that the United States was not at war and defined the military effort as a "police action."

Truman's behavior inspired few objections at first, but as the war became a stalemate, opposition grew. In 1951 he sent forces to Europe, and after a long debate, the Senate passed a non-binding resolution reclaiming the power to approve troop assignments in advance. In 1952 Truman seized steel plants whose workers threatened to strike in order to maintain Korean War production, but the Supreme Court ruled that the move overstepped executive authority. Nevertheless, presidential war power continued to grow.

After two apparent North Vietnamese attacks on American destroyers in the Gulf of Tonkin in 1964, Lyndon Johnson sought congressional approval to retaliate. (In fact, reports on one of the North Vietnamese attacks relied on questionable sonar readings, and there is considerable evidence that it never happened.) Both houses responded immediately with the Gulf of Tonkin Resolution, which allowed the use of force "to repel any armed attack" and "to prevent further aggression." Though the resolution was clearly limited in scope, the American troop commitment grew from 18,000 to 125,000 within a year. It would soon exceed 500,000.

As with Korea, Congress tried to exert its war power only after the fact, when the Vietnam War had become a disaster. In 1969 the Senate passed a non-binding resolution urging executive and legislative cooperation. In 1973 Congress finally passed a binding measure, the War Powers Resolution, requiring the president to get legislative approval before sending troops into long-term combat.

Recent presidents, however, have taken advantage of several loopholes in the War Powers Act, most notably a clause that allows presidentially declared wars lasting 60 days or less. Ronald Reagan's interventions in Lebanon (1982) and Libya (1986) lacked congressional approval, and while George H. W. Bush received authorization for the Persian Gulf War (1991), he ordered the invasion of Panama (1989) while Congress was out of session. Bill Clinton acted unilaterally in Iraq (1993, 1998), Haiti (1994), and Bosnia (1995). Congress gave limited approval to the war in Afghanistan in 2001. On September 12, the day after the attacks on the World Trade Center and the Pentagon, a joint resolution supported "the determination of the President, in close consultation with Congress, to bring to justice and punish the perpetrators of these attacks as well as their sponsors."

Recent arguments in favor of presidential war power claim that the framers did not anticipate modern warfare, which occurs in a fast-moving global context and depends on speed and secrecy. Advocates of congressional authority maintain that the decision to commit the country to war should not belong to a single person, but they have yet to make the case consistently or vigorously enough to reverse the long historical trend.


Fisher, Louis. Presidential War Power. Lawrence: University Press of Kansas, 1995.

Hess, Gary R. Presidential Decisions for War: Korea, Vietnam, and the Persian Gulf. Baltimore: Johns Hopkins University Press, 2001.

Javits, Jacob K. Who Makes War: The President Versus Congress. New York: Morrow, 1973.

Lehman, John F. Making War: The 200-Year-Old Battle Between the President and Congress over How America Goes to War. New York: Scribners, 1992.

Westerfield, Donald L. War Powers: The President, the Congress, and the Question of War. Westport, Conn.: Praeger, 1996.


See alsoChecks and Balances ; War, Laws of .

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war powers

war powers In the USA, constitutional powers given to the president as supreme military commander. They include the power to appoint armed forces officers with consent of Senate. Congress alone is empowered to declare war, but presidents have carried out military actions without congressional approval or a formal declaration of war, as in ordering troops into Korea and Vietnam.

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