Julian E. Zelizer: War Powers belong to Congress and the President

Julian E. Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter," published by Times Books, and editor of a book assessing former President George W. Bush's administration, published by Princeton University Press.

When presidents send American troops into military conflict, it usually seems as if Congress barely flinches. Presidents no longer request that Congress declare war. Members of Congress don't insist that presidents ask them.

Still, tension over military action can develop between the White House and Congress. In the most recent chapter of the nation's inter-branch conflict, Speaker of the House John Boehner has charged that President Barack Obama violated the War Powers Resolution, which Congress passed in 1973 in an effort to seize war power back from the executive branch.

Obama is being criticized because he did not request congressional approval of the military operations in Libya even though they have lasted for more than 90 days. In a symbolic vote, 225 Republicans allied with 70 Democrats to vote down a measure authorizing the operations in Libya. They did not vote to cut funding, however.

While the speaker has raised an important point, the fact is that all presidents, Democrats and Republicans, have made decisions about sending troops into conflict without a declaration of war. Since President Harry Truman sent troops into Korea in 1950, legislators have let presidents make the initial decision as to whether military force should be used.

Although Congress has remained quite active in wartime politics, ranging from its use of hearings to stimulate political debate to the shaping of military budgets, Congress no longer declares war. Before the Korean War, the situation was quite different....