Kudos to President Obama.

On Friday afternoon, the Commander-in-Chief was ready to flout the Constitution and start the second illegal war of his presidency. Then he seemingly had a change of heart and decided to obey the law.

Obama's 2011 war in Libya was still illegal. His current plan to attack Syria still seems ill-advised. But the president deserves one cheer for trying to launch this war of choice according to the rule of law.

If that seems like a low standard, don't blame Obama. Presidents seizing war powers -- and Congress ceding them -- is a well-established American tradition.

Let's start with the law. The Constitution gives Congress, and only Congress, the power "To declare war, grant letters of marque and reprisal, and make rules concerning captures on land and water ...."

James Madison crafted that language at the Constitutional Convention, changing the phrase "make war" in an earlier draft to "declare war." This change was seemingly aimed at allowing the president to defend the U.S. from an attack, but bar him from entering the country into a war of choice. Roger Sherman, a delegate from Connecticut, supported Madison's language, saying, "the Executive should be able to repel and not to commence war."

One of the first tests of the Constitution's war powers provisions came in 1793 when Gen. Andrew Pickens wrote George Washington that "a demonstration of the power of the United States to punish the Creek [Indians] is the only measure which can be adopted to secure from their cruel depredations the Inhabitants of the South Western frontiers."

Washington's view on the matter, as quoted by conservative journalist Terence Jeffrey of CNSNews: "The Constitution vests the power of declaring war with Congress; therefore no offensive expedition of importance can be undertaken until after they shall have deliberated upon the subject, and authorized such a measure."

"No offensive expedition of importance," without Congressional approval was Washington's standard -- the same as Madison's.

Congress tried to codify this understanding in 1973 with the War Powers Resolution. The resolution stated the president could "introduce United States Armed Forces into hostilities" only in the case of "(1) a declaration of war, (2) specific statutory authorization, or (3) a national emergency created by attack upon the United States, its territories or possessions, or its armed forces."

As a senator, Obama agreed with this view. "The president does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation," Obama said in 2007.

But that's not how presidents have actually behaved, at least not since after World War II. Harry Truman never got a declaration of war against North Korea, instead calling it a "police action." Vietnam was an undeclared war, too, and at first our troops there were called "military advisors." By the time it was over, 58,000 American soldiers had been killed. Bill Clinton never got permission to bomb Bosnia, arguing he was just enforcing a peace treaty.

President George W. Bush, at least, got congressional authorization for his attacks on Afghanistan and Iraq. Obama, of course, intervened in Libya's civil war without congressional authorization. His administration explained this wasn't war, it was merely a "kinetic military action" that would last "days, not weeks."

Obama and Secretary of State John Kerry on Friday intimated that the administration didn't feel the need to get a vote from Congress to attack Syria. Both suggested that "consultation" with Congress would be sufficient. That seemed to mean mostly briefing congressional leaders.

"Congressional leaders are not 'Congress,' " Rep. Justin Amash fumed on Twitter. "And [Obama] needs approval, not consultation."

Amash articulated the feelings of more than 140 members of Congress -- mostly Republicans -- who signed a letter demanding Obama get congressional approval before war.

And, to Obama's credit, he listened, promising Saturday to seek congressional authorization before attacking Syria.

If congressmen feel bound to support the war, they should learn from the mistake of the post-Sept. 11 Authorization of the Use of Military Force -- which is still being used today to justify drone strikes in Yemen -- and tailor its authorization as narrowly as possible. Limit the authorization in scope, geography and time.

Obama says no boots on the ground, so put that in the law. Obama says it won't be open-ended, so put a sunset date on the authorization.

Congress shouldn't be afraid to take back some of its rightful authority over war -- even if it means a break with tradition.

Timothy P. Carney, the Washington Examiner's senior political columnist, can be contacted at tcarney@washingtonexaminer.com. His column appears Sunday and Wednesday on washingtonexaminer.com.