It was one of the more embarrassing moments in an embarrassing year — decade? — for Congress. As Islamic State rampaged through Syria and Iraq over the summer, Congress stayed on vacation rather than debate and vote on a broad resolution authorizing the president to respond. No one, including the president, wanted to risk a public debate on U.S. anti-terrorism efforts before the November election.

The election is over — Democrats avoided the war debate but lost the Senate anyway — and now President Barack Obama is asking Congress for a resolution authorizing the use of force against Islamic State.

The president wants permission to engage, but he also wants Congress to tie his hands. He’s asking Congress to sign off on a plan to fight a limited war that excludes “enduring offensive ground combat operations.” He would tie the hands of the next president by setting a three-year expiration on the resolution.

The president doesn’t actually require a resolution to act. The U.S. and its allies have launched more than 2,000 airstrikes against Islamic State in Iraq and Syria. More than 2,600 American troops are on the ground helping the beleaguered Iraqi military get its act in gear.

Legal justification to respond to Islamic State already exists because, while the enemy has a new name, this is basically a continuation of the war on terror. The authority granted in 2001 to fight al-Qaida, still in place, remains valid against Islamic State.

This is a war that may go on for some time, and get even more complicated than it has been. Islamic State controls a vast sweep of territory and represents a clear threat to the Middle East, to American interests there and to our national security. Mosul — Iraq’s second-largest city — is occupied by Islamic State. Four Americans who fell into the militant group’s hands have been killed, three by gruesome beheading. A captured Jordanian air force pilot was burned alive. Islamic State has been recruiting and training people from around the world, including the U.S.

Passing a congressional resolution would be a full-throated declaration by the members of Congress that they support the use of military force in this fight against terrorism. It would send a message to our allies, and our enemy, that America is committed to this.

The president plans for continued airstrikes by the U.S. and continued cooperation with our allies. A vital phalanx from the Middle East — Bahrain, Jordan, Saudi Arabia and the United Arab Emirates — is flying sorties against Islamic State in Syria.

Controlling the skies is crucial. Over the past several months, airstrikes have taken a toll on Islamic State, whose land-grabbing ability now appears stalled. But this is a war that will be won or lost on the ground. Kurdish peshmerga forces have driven Islamic State from some territory. Not much more will happen until the hapless Iraqi army gets on its feet after its embarrassing collapse last year, which gave Islamic State free rein to push nearly to Baghdad.

Obama believes the key to defeating Islamic State lies with those local forces. The peshmerga and Iran-backed Shiite militias are doing most of the fighting now, while the U.S. retrains the Iraqi army. It will be months before there’s any hope of dislodging the enemy from Mosul.

Under the president’s proposed authorization, the U.S. would ramp up its fighting capacity, but only to a point. He seeks permission to conduct limited U.S. ground combat operations, including rescue missions, the use of special operations forces to take out Islamic State leaders, intelligence gathering, planning and other assistance.

Perhaps the bid to rule out “enduring offensive ground combat operations” is intended to collect the votes of Democrats who are wary of any combat operations. Nevertheless, Democrats are objecting to the scope of the resolution. And Republicans are objecting to the narrowness of the resolution.

Few people anticipate a substantial deployment of U.S. ground troops, “enduring” or not. But no one can predict how the war to defeat Islamic State will go. It’s a chaotic situation, involving an unpredictable foe against a coalition that includes a feeble Iraqi force and a motley collection of militias in one of the most unstable regions of the globe.

Congress should give the president broader authority. Taking away options and setting a timetable constrains our ability, complicates later decision-making and helps the enemy.

Give the president the authority he needs, not the authority he seeks.

— Chicago Tribune