But in Congress, where there is considerable opposition to the war in Iraq and to the President's plan for a troop "surge," some lawmakers say the President's authority to make war is far from absolute.
"I suggest we are coequalCongress, along with the Presidentin deciding when, if, how long, and under what circumstances to send Americans to war," said Senator Joseph Biden of Delaware, who opposes the President's plan.
The question of who can send American troops to warthe President or Congresshas been debated in Washington for more than 200 years. The Constitution divides war powers between the executive and legislative branches, but the language is open to interpretation.
The Constitution says: "The President shall be Commander in Chief of the Army and Navy of the United States." (There was no Air Force or Coast Guard in 1789, and the Marine Corps was, and is, technically part of the Navy.) Today, the heads of all five branches of the military ultimately take their orders from the President.
But the Constitution also says: "The Congress shall have power … to declare war" and to "provide for the common defense ... of the United States." And since Congress also controls federal spendingwhat's known as "the power of the purse"it has the authority to decide whether to fund a war.
At the very least, the Founding Fathers seem to have wanted Congress to have some say in matters of war. "In no part of the Constitution is more wisdom to be found than in the clause which confides the question of war and peace to the legislature, and not to the executive department," James Madison wrote in 1793.
Five Formal Declarations
Congress has formally declared war only five times (see timeline below), but Presidents have sent troops to fight abroad more than 200 times, including various interventions in Central America, the war in Vietnam, and the current conflicts in Afghanistan and Iraq. Usually, there has been some kind of congressional assent beforehand, but not always.
"From Washington forward, Presidents have engaged in military activities without declarations and without authorizations," says Matthew Spaulding of the Heritage Foundation.
But since the Vietnam War, which lasted more than a decade and divided the nation, the issue of presidential vs. congressional authority in wartime has come up many times. In the late 1960s, as the number of Americans killed in Vietnam rose (eventually reaching 58,000), there was increasing pressure to end the war. Congress responded in 1970 by barring the use of any funds for troops in neighboring Cambodia, to which the war had spread. And in 1973, after President Richard M. Nixon agreed to withdraw U.S. troops from Vietnam, Congress set a date after which no funds could be used to support combat in Southeast Asia.
War Powers Act
Congress went a step further that year by passing the War Powers Act, which requires a President to terminate the use of force after 90 days unless Congress has authorized it. The act became law after Congress overrode Nixon's veto, but it has essentially been ignored by every President since then. It has never been constitutionally tested in the courts.
In the 1980s, the debate over war powers focused on President Ronald Reagan's desire to provide military aid to the Contras, an anti-Communist insurgent group in Nicaragua. After Congress cut off funding, the administration secretly and illegally sold weapons to Iran and used some of the money to fund the Contras. The discovery of the operation led to the scandal known as Iran-Contra.
Considering the long-running tug of war over who controls the nation's military operations, it's not surprising that the issue has surfaced again with the U.S. bogged down in Iraq.
The November election that gave Democrats majorities in the House and Senate was widely viewed as a repudiation of the Bush administration's management of the war. But since Bush announced the troop buildup, Democrats in Congressand some Republicanshave struggled with how to respond. (The Pentagon expects about 14,000 additional troops to be on the ground in Iraq by late April.)
In February, the House passed a nonbinding resolution expressing disapproval of the troop buildup plan. In March, Democrats in the House and Senate began considering proposals that set a timetable for a U.S. troop withdrawal.
The Senate has also considered revoking the broad 2002 Iraq war authorization, or rewriting it to significantly narrow the military mission. Given how closely divided Congress is, any of these measures would likely end up as symbolic gestures, since they would probably not have enough support to override Bush's almost certain veto.
But Thomas Mann of the Brookings Institution says that Congress has a power that's not specified in the Constitution: its political influence. "Just because it's not binding doesn't mean it's meaningless," he says. "Congress's great leverage is political, not legal or constitutional."
There is little dispute that Congress could, if it had the political will, end the war in Iraq almost immediately by using its power over appropriations to cut off funds for the troops. "Congress could easily check the President," says W. Taylor Reveley III, author of War Powers of the President and Congress. "If Iraq continues to go badly … I can easily see Congress passing something like the Cambodian or Vietnam spending cutoffs, which would force the setting of a timetable for withdrawal that was pretty brisk."
If Congress used its appropriations power in this way, even the most vigorous defenders of executive power agree, President Bush would have to acquiesce. "He would have to comply, and he would comply," says John C. Yoo, a former Bush administration official.
'A Very Serious Weapon'
But most experts agree it would be politically suicidal for Congress to cut off funding while there are troops in harm's way. "I think there's a broad recognition that when you have forces in the field, de-funding is a very serious weapon to wield," says Spaulding of the Heritage Foundation.
Does Congress have other options? It clearly has the power to declare war, but does that imply the power to un-declare it? That is, in effect, what the Senate is grappling with by trying to revoke or rewrite the Iraq war authorization.
Legal scholars agree that the Founding Fathers divided war powers partly to prevent Congress from intervening in the tactical decisions of a war. It is often said you cannot have 535 generals (100 Senators and 435 Representatives). From President Bush's perspective, any effort in Congress to prevent him from sending more troops to Iraq is just the kind of interference the Constitution aims to prevent.
"Every time we've gotten involved in an unpopular war, which has been all our wars except the two World Wars, there has been an enormous amount of bickering between the President and Congress when it didn't come out the way we wanted," says Reveley. "Sometimes Presidents have acted, [then] Congress said 'Don't do that,' and the President acceded, as in Vietnam. But mostly Congress has stood on the sidelines and complained."
No matter how the current debate is resolved, Congress could react by trying to assert its powers over future Presidents.
"Congress will be much more careful in the future about authorizing force without restrictions on presidential power," says Jack Goldsmith, a professor at Harvard Law School. "Every action on each side tends to provoke a counterreaction, which is probably what James Madison wanted."