The terrorist attacks on Paris last week and the current lockdown in the Belgian city of Brussels, where officials fear ISIS fighters are planning similar attacks, have highlighted the group's ability to sow death and destruction far beyond the territories it controls in Iraq and Syria. Clearly the U.S. and its European allies are not winning the struggle against Islamic terrorism, no matter how many times they declare, as did President François Hollande of France last week, that they are "at war" with ISIS. The U.S. needs to assume a stronger role in coordinating the anti-ISIS coalition and step up its intervention in the region, both military and diplomatic.
At present, ISIS is benefiting greatly from the strategic confusion among its opponents. Saudi Arabia appears more concerned with toppling Syrian President Bashar Assad and checking Iran's influence in the region than with defeating ISIS. Turkey, likewise, seems more intent on ousting Mr. Assad and putting down separatist Kurds than in defeating the terrorists on its doorstep. Russia and Iran remain willfully blind to ISIS' depredations in their zeal to ensure Mr. Assad's hold on power, while Iraq refuses to arm its Sunni tribes against the group for fear they may threaten the Shiite dominated government in Baghdad.
Only the U.S. and Europe have made defeating ISIS their priority, but that has put them at odds with all their potential allies and their conflicting agendas. The U.S. is the only major power that can break this destructive political logjam, and it needs to begin doing so quickly before the situation gets even worse.
The Republican presidential candidates have issued simplistic calls for putting more U.S. boots on the ground, but President Obama is right to be skeptical of that approach. Introducing thousands of U.S. or NATO troops into the conflict zone would risk a dangerous collision with Russian troops and aircraft already operating in the region, which would only deepen the crisis.
Mr. Obama's strategy of supporting moderate Syrian rebels and Kurdish militias on the ground through airstrikes, intelligence and logistics support along with small contingents of U.S. Special Operations troops is fundamentally sound, but by themselves those forces are still too weak to decisively oust ISIS from its fortified strongholds. The U.S. must persuade the Gulf Arab states, Jordan and Turkey to contribute their own ground forces to the battle under U.S. and NATO air cover.
There's also an argument to be made that troops from Muslim countries would be more effective against ISIS in the long run than either the U.S. or NATO. Besides the fact that ISIS is a greater threat to them than it is to us, a defeat suffered by ISIS at the hands of other Muslims rather than by Western "crusaders" would seriously undercut the group's ideological claims of being champions of Islam against foreign unbelievers.
Moreover, the U.S. and Europe have other reasons to be careful about how ISIS is eventually defeated. Brookings Institution scholar J. M. Berger argues that even if U.S. and NATO forces drive ISIS out of the territories it now controls, such a victory might have disastrous unanticipated consequences. "Thousands of angry young men who were manning checkpoints and policing the streets for ISIS will be freed to commit terrorism instead," he warns. The result could be a wave a terrorism "the likes of which the world has never seen."
Underlying all these concerns is the hard reality that there is probably no solution to the threat ISIS poses as long as Mr. Assad remains in power. He has created the failed state his country has become and along with it the power vacuum that has allowed ISIS to flourish. And it is Russia's and Iran's insistence on propping up his rule that blocks any hope of a political resolution to the conflict. At some point, Russian President Vladimir Putin may make the strategic judgment that his country's interests in Syria can be protected by someone other than Mr. Assad and that he can safely help ease the dictator out. But he shows no inclination to move in that direction at the moment, and even if he were to do so there's no guarantee the mullahs in Tehran would follow suit.
The strategic confusion among ISIS' opponents has hurt Mr. Obama and his measured approach to the use of military force. Americans want to be reassured, and they are understandably frustrated that he hasn't reacted more aggressively after the Paris attacks. But the Republican candidates' vague and simplistic proposals for "getting tough" on ISIS aren't a strategy for victory, much less a solution to the problem of how the U.S. can form an effective anti-ISIS coalition that secures the interests of our NATO partners and Arab allies while preventing Russia and Iran from expanding their influence in the region.
Democratic presidential candidate Hillary Clinton seems to recognize that allying ourselves with Russia and Iran against ISIS would only prolong Mr. Assad's hold on power and that the key to ending his misrule lies in pressuring Russia and Iran to stop backing Mr. Assad while upping the military pressure on him, including possibly using U.S. airpower to establish no-fly zones where moderate rebels and Kurdish forces can be trained and equipped.
Ms. Clinton's ideas notably depart from the course adopted by Mr. Obama, who so far has sought to minimize the U.S. military footprint in Syria, and they come with risks of which we are wary. But given the heightened threat ISIS poses to the West in the wake of the Paris attacks, they may be the only way to halt Syria's descent into even worse chaos.