Even as the smoke clears from last week’s U.S. missile strike on a Syrian air base, the future is shrouded in fog. It’s not clear what President Trump’s ultimate goal will turn out to be, what military methods he may use, whether he will have public support or whether he will succeed.

What is clear is that the decisions should not be his alone. The Constitution assigns to Congress, not the president, the power to declare war. Even though recent practice and modern technology have rendered that provision toothless, Congress has the right and the duty to take a role in deciding whether American lives and resources should be put in harm’s way in Syria.

The experience under Trump’s immediate predecessor is an indictment of both Barack Obama and the legislative branch. He took the nation to war in Libya in 2011 without asking for congressional authorization. He also disdained the requirements of the 1973 War Powers Resolution — which says the president has 60 to 90 days after commencing hostilities to get approval from Congress or end the military operation.

Obama did request congressional approval in 2013 for an attack on Syria, but failed to get it and backed off. In 2015, well after he began bombing Islamic State of Syria and Iraq positions, he asked for a resolution supporting the campaign. But when lawmakers did nothing, he didn’t let that keep him from proceeding as before.

For too long, presidents have been able to monopolize these decisions because nobody else wanted them. And if Congress wasn’t willing to bless the operations, its members should have voted the resolution down. They should not repeat that spineless performance.

The point is not that Trump should be prevented from additional attacks against the forces of Syrian President Bashar Assad, who provoked this strike by using chemical weapons. The point is that when the president goes to war, even on a limited scale, he — and, more important, the world — should know the nation is firmly committed to that mission.

By authorizing action against Assad, Congress would encourage members to stick with the fight even if it gets tough, while giving the administration confidence it can count on the resources it needs. By rejecting action, on the other hand, lawmakers would force the president to ponder the wisdom of starting a war over the opposition of the people’s representatives.