When President Obama announced an international campaign to “degrade and ultimately destroy” the Islamic State in Iraq and the Levant (ISIL) last year, the organization was primarily a regional threat, inflicting its savagery on the people of Iraq and Syria and on hostages from other countries who were captured in the Middle East. But the coordinated attacks in Paris that killed 130 people and the downing of a Russian airliner suggest that the organization has embarked on a campaign of exporting terror globally.

In an editorial after the Paris attacks, we counseled against a sudden lurch in what Obama has called “a steady, relentless effort” against ISIL, which so far has consisted of using U.S. air power and relying on local forces to fight the ground battles.

But the U.S. and its allies can and should increase the pressure on ISIL in Syria and Iraq in recognition of the group’s expanding agenda, and without committing the U.S. to provide “boots on the ground.” The administration reportedly is considering tripling the 50 special operations forces Obama has said he will dispatch to Syria, and the Pentagon may increase the frequency and severity of U.S. airstrikes, especially those targeting oil facilities, which provide a source of revenue for ISIL. (The administration should be careful, however, not to loosen restrictions designed to minimize civilian casualties.)

In a thoughtful speech last week on the presidential campaign trail, former Secretary of State Hillary Clinton called for regional powers such as Jordan and Turkey to play a larger role in combating ISIL. But she also suggested a more flexible role for the more than 3,000 U.S. forces now serving in Iraq as trainers and advisers. She would allow U.S. personnel to be embedded with Iraqi units and to help call in airstrikes. Admittedly, such a change in posture would increase the risk that U.S. forces would come under fire, but it also could improve the effectiveness of operations against ISIL strongholds.

There are two main objections to the U.S. ratcheting up its military involvement. One is that it will be too incremental to make much difference in the war zone. That’s true of any limited use of U.S. power, yet it’s not a persuasive argument for the U.S. waging another ground war in the Middle East.

A related concern is that, if these steps do fall short, Obama and his military advisers eventually will be tempted to escalate further. This is the familiar “quagmire” argument, and it can’t be blithely dismissed. But it’s also a rationale for taking no action, ever. A better safeguard against that kind of escalation would be for Congress to belatedly adopt an Authorization for Use of Military Force against ISIL that would hold Obama to his promise that he won’t deploy combat troops in the region.

Clinton and many of the Republican presidential candidates have gone further, calling for the creation of no-fly zones to prevent the government of Syrian President Bashar Assad from assaulting civilians and opponents from the air. The problem with this proposal is that it would be difficult to establish such areas safely without the cooperation of Russia, which also is conducting airstrikes in Syria. That underlines the importance of the U.S. continuing to work with Russia and other countries to bring about a political transition in Syria that preserves government institutions there while giving the Syrian people the opportunity to choose new leadership.