Their View | Obama’s half-hearted punch

An unlikely consensus is emerging across the ideological spectrum about the war against the Islamic State: President Barack Obama’s strategy to “degrade and eventually destroy” the terrorist entity is unworkable. It’s not just that, as some administration officials say, more time is needed to accomplish complex tasks such as training Iraqi and Syrian forces. It’s that the military means the president has authorized cannot accomplish his announced aims.

As Islamic State forces continue to advance in Iraq’s Anbar province while besieging the Syrian Kurdish city of Kobani, major weaknesses in the U.S.-led campaign have become apparent. One is a relatively modest tempo of airstrikes that in several cases has not been able to turn back advances by enemy forces. Another is the absence of ground trainers, advisers and special forces who could accompany Iraqi and Syrian forces, call in airstrikes and medical assistance, and help formulate tactics. A third is a de facto stance of neutrality toward the Syrian regime of Bashar Assad, a stance that has allowed the regime to launch new offensives against the same rebel forces the United States is counting on to fight the Islamic State.

The limitations to the U.S. effort, which were mostly imposed by Obama, are prompting blunt assessments from senior Pentagon officials. “We need a credible, moderate Syrian force, but we have not been willing to commit what it takes to build that force,” one told The Post’s Rajiv Chandrasekaran. Said another officer: “You cannot field an effective force if you’re not on the ground to advise and assist them.”

U.S. allies are also reacting to the holes in the strategy. Turkey has withheld military cooperation because of the absence of a strategy to counter the Assad regime. The new Iraqi government, which Obama has been pushing to reach out to the country’s Sunni tribes, just appointed a member of a murderous Iranian-sponsored Shiite militia to head the Interior Ministry. Sunni tribesmen, for their part, are choosing to strike deals with the Islamic State rather than support the U.S. coalition. Leaders of the Free Syrian Army are asking why U.S. warplanes are attempting to rescue Kobani while allowing Assad’s forces to encircle and rain barrel bombs on rebel-held positions in Aleppo.

Some on both the left and right in Washington are arguing that the appropriate response to the campaign’s deficiencies is for Obama to lower his ambitions; he should seek merely to prevent further expansion by the Islamic State or attacks on the homeland. The problem with a policy of containment, however, is that the infection of the Islamic State is spreading.

Militant groups around the region are rallying to its cause, volunteers continue to travel to Syria, and popular support for it is dangerously evident in countries such as Turkey, Lebanon and Jordan.

Obama has been right to fashion a broad coalition against the Islamic State and to try to build on local forces. But the United States will have to broaden its aims and increase its military commitment if the terrorists are to be defeated.

At the least, Syrian rebel forces must be protected from attacks by the Assad regime and both Syrian and Iraqi units provided with U.S. advisers and air controllers.

The longer Obama delays such steps, the greater the risk to vital U.S. interests.