A coordinated attack on Syria

President Trump has sometimes seemed to view military action as a game and foreign policy as something set by online taunts. He seemed to think that as commander in chief he could simply follow his whims.

So it was reassuring that his military response to a suspected chemical attack that killed dozens of people in the rebel-held Damascus suburb of Douma on April 7 was coordinated with Britain and France. In his address to the nation Friday night, he said that preventing the use of chemical weapons was in the “vital national security interest of the United States.”

Earlier this week we got his usual bluster. “Get ready Russia, because they will be coming, nice and new and ‘smart,’” the president said on Twitter on Wednesday, in his best movie tough-guy impersonation, after a Russian diplomat warned that his nation’s forces would shoot down any missile fired at their ally Syria. On Friday night his message to the Syrian regime’s two main defenders, Russia and Iran, was more measured. “What kind of a nation wants to be associated with the mass murder of innocent men, women and children?” he asked. “The nations of the world can be judged by the friends they keep.”

Defense Secretary Jim Mattis said that while this was a “one-off” attack, like the airstrike against Syria a year ago, the targets were involved in the production and storage of chemical agents, not just an airfield. He warned of further attacks if Syria used chemical weapons again.

The attack in Douma was an outrage. Photos showed children foaming from their mouths and nostrils. The World Health Organization reported that 500 people in Douma had symptoms of exposure to chemical weapons, and many of those who died had signs of “highly toxic chemicals.”

Mr. Mattis had tried to slow the rush to a military strike in part because he felt he needed more evidence to corroborate the charges against the Syrian government. But on Friday night he attributed the chemical attack to the regime of Bashar al-Assad.

Mr. Mattis was also said to be concerned that a bombing campaign could lead to a wider conflict with Russia and Iran, in a battlespace already teeming with competing Syrian factions, terrorists, and forces of the United States and other foreign powers. America has 2,000 troops on the ground fighting ISIS, and Syria has said it would defend itself. Mr. Mattis said on Friday night that targets were chosen to reduce the risk of hitting non-Syrian forces.

Still, Mr. Mattis’s willingness and ability to stand up to Mr. Trump’s rants, and to maintain his trust, in an administration largely stocked with sycophants

might be the only things that keep the United States out of deeper, poorly planned, military engagements.

Under the United Nations Charter, there are two justifications for using force against another country without its consent: in self-defense and with the United Nations Security Council’s permission. The former does not apply in this case, and the latter would be impossible, given Russia’s veto power in the Council.

Under the Constitution, war powers are divided between Congress and the president. In the view of most legal scholars, America’s founders wanted Congress to decide when to go to war, except when the country is under attack. Since World War II, presidents from both parties have pushed the boundaries of executive authority and carried out many military operations without congressional authorizations, as Mr. Trump did last year when he ordered 59 cruise missiles fired against Syrian targets after a sarin gas attack on the rebel-held town of Khan Sheikhoun.

The War Powers Act in 1973 was supposed to allow Congress to reclaim some of its clout, but its record in circumscribing the president’s authority to use military forces in hostilities overseas is mixed. In recent years, executive branch lawyers have concluded that presidents may act unilaterally if they decide that a strike would be in the national interest and that it would fall short of an all-out war involving ground troops. Congress has largely acquiesced.

Two notable exceptions are the Authorizations for the Use of Military Force that were passed in 2001 and 2002 after the Sept. 11 attacks to cover American-led operations in Afghanistan and Iraq, respectively. The 2001 legislation was aimed at Al Qaeda and the Taliban; the 2002 legislation focused on the threat from the Iraqi leader Saddam Hussein.

Since then, President Barack Obama and now Mr. Trump have used those same authorizations at least 37 times to justify attacks on the Islamic State and other militant groups in 14 countries, including Yemen, the Philippines, Kenya, Eritrea and Niger, according to Dan Grazier of the Project on Government Oversight. This has allowed the Republican-led Congress to avoid public debate — and any responsibility for sending American men and women into battle.

This interpretation of the law gives a free hand to the volatile and thoughtless Mr. Trump, which could prove even more dangerous if he were to decide to attack North Korea or Iran.

After a relentless push by Senator Tim Kaine, a Virginia Democrat, Bob Corker, who is the chairman of the Senate Foreign Relations Committee and a Tennessee Republican, is soon expected to propose a new authorization to deal with military operations against nonstate actors like ISIS.

But legislation should also set limits on a president’s ability to wage war against states like Syria. Without that, Congress would be once again abdicating its responsibility and ceding broad powers to an impulsive president with dubious judgment.