IF HISTORY is any guide, President Obama could probably get away with ordering a military strike on Syria without first getting congressional authorization. Yes, the Constitution grants Congress the exclusive right to declare war. And yes, the 1973 War Powers Resolution legislated congressional control over presidentially initiated uses of force. But President Harry S. Truman sent troops to Korea in 1950 without Congress’s permission; President Bill Clinton carried out a 78-day air campaign against Yugoslavia in 1999, despite the War Powers Resolution’s 60-day limit; and two years ago, Mr. Obama committed U.S. planes and other military assets to support British and French airstrikes in Libya. In our view, history has vindicated all three actions.

Still, should the president act unilaterally now? The legal authorities his administration has informally cited are slender indeed — slimmer, even, than the U.N. Security Council resolution upon which the Libya mission rested. Officials have suggested that the international norm against the use of chemical weapons is tantamount to a legal prohibition and that punishing and deterring Syrian violations warrants a brief, limited use of force.

Mr. Obama has consulted congressional leaders; but this is a far cry from the full-blown debate and vote that more than 100 members of the House have called for in a bipartisan letter to the president. Meanwhile, British Prime Minister David Cameron has called Parliament into session to discuss Syria, and his government will pursue a U.N. Security Council resolution — albeit with little chance of success, given Russia’s likely veto on behalf of its Syrian clients.

Under the circumstances, the president would be wise to seek the maximum feasible congressional involvement. This is only partly a judgment about what’s constitutionally and legally sound; it’s also a judgment about what’s politically optimal. The more Congress shares in the burden of decision-making, consistent with the operational necessities of the prospective mission, the more legitimate the ultimate decision will be.

Obviously, the risk is that Congress would deny Mr. Obama power to enforce his “red line” — or would unduly delay it. That this risk exists, alas, partly reflects Mr. Obama’s past reluctance to educate public opinion about the stakes in Syria, which, in turn, reflects his reluctance to get more deeply involved there. But now that U.S. credibility is at stake, we doubt that Congress, even one partially controlled by Mr. Obama’s partisan enemies, would weaken the commander in chief, and the nation, in a confrontation with implications that extend well beyond Syria.

Mr. Obama must know that Congress will engage more deeply on Syria sooner or later. Even a short, sharp strike such as the one he reportedly contemplates is unlikely to be the last act in this drama. Nor, in our view, should it be. Unless linked to a broader strategy for weakening the Assad regime — and forcing it either out of power or into real negotiations — the use of force might prove worse than useless. Mr. Obama can and should formulate a sustainable strategy and then make a convincing case for it to the American people and their elected representatives.