In our system of government, the Constitution grants no greater power to Congress than the power to declare war and commit the nation’s military might and the lives of its soldiers to armed conflict. Presidents may ask Congress for a declaration of war, but only Congress — the representative of the American people — can lead us into conflict.

But especially in the last two decades, beginning with the early years of the War on Terror in the late 1990s, presidents of both parties have initiated military action with only perfunctory involvement of Congress. The legislative branch has been perfectly willing to let the executive shoulder the political risk. Libya. The so-called Islamic State. Nigeria. Syria. It’s a constitutional imbalance that, quite simply, puts more power in the hands of the president than the Framers ever intended.

And that’s why Virginia’s Sen. Tim Kaine has fought so hard over the years to restore Congress to its proper seat at the table when such decisions are being made. This bipartisan battle he’s waged, alongside Arizona Republican Jeff Flake and Tennessee Republican Bob Corker, has been long and lonely as, first, former President Barack Obama and now President Trump have used U.S. military might in far-flung action in the world with barely a nod to Congress.

But the Framers of the Constitution couldn’t have foreseen the ways in which a 21st century superpower would have to act on the global stage. Not every conflict or military action would rise to the level of an official declaration of war, but somehow, in the spirit of the Constitution, the concept of Congress as the ultimate political power had to be preserved.

And thus was born the concept of the AUMF — Authorization for Use of Military Force. The executive would come to Congress with a detailed plan for dealing with some national security threat. The two branches would negotiate the shape of the document and its goals and exit strategy and, ideally, a united nation would then act.

But that’s not how it’s worked out, for the most part, hence the frustration of Kaine and others in Congress.

In taking on the Islamic State, Obama relied on the AUMF Congress had passed in the wake of the Sept. 11, 2001, terrorist attacks, even though ISIS had nothing to do with 9-11. When pressed to seek authorization from Congress for this new conflict, he presented one limited in scope and duration; congressional Republicans countered with one more open-ended and broader; and neither party bothered to do much negotiating after that. Congress was willing and content to shuffle the risks of action onto the White House.

Today, with Syrian dictator Bashar al-Assad’s use of chemical weapons against his own people, the need for a unified America to act is ever greater.

Assad has been waging a bloody war against his own people who rose up to demand democratic change seven years ago in the Arab Spring. Twice in the last 12 months or so, Assad unleashed chemical weapons on rebel-held towns, killing dozens if not hundreds of people. Twice President Trump has responded with cruise missile attacks targeted on Syrian military sites, the most recent being the week before last. And Trump, like Obama before him in similar situations, gave only a perfunctory nod to Congress.

It is perfectly understandable that use of chemical agents in conflicts today generates such outrage. The photos from the scenes of the attacks prick the conscience of the world; we feel as though something, anything, must be done to punish a dictator who would so mercilessly attack his own citizens.

But nations, especially superpowers, can’t act solely on emotion. There are laws and Constitutional strictures to be followed, none more important than the notion that Congress alone has the power to commit the nation to military action.

It’s been a lonely, almost-10-year-long battle for Kaine and his allies, under both a Democratic and a Republican president, neither of whom wanted to be chafed by Congress, and with one Congress after another that was all too willing to cede its duties if it didn’t have to shoulder any of the risks. But it’s a fight we believe Kaine is right to wage, for when government feels few restrictions on its global actions, how much longer before it feels few restrictions on its actions at home?