President Obama’s neglect of the anti-terrorism march in Paris seemed reflective of a broader loss of momentum by his administration in combating Islamic jihadism. Five months after the president launched military operations against the Islamic State, fighting in Iraq and Syria appears stalemated. The training of Iraqi army units for a hoped-for counteroffensive is proceeding slowly and, according to a report by The Post’s Loveday Morris, looks under-resourced. Weapons and ammunition are in such short supply that trainees are yelling “bang, bang” in place of shooting.

Iraq, moreover, is the theater where U.S. engagement is most aggressive; elsewhere, the Obama administration appears to be passively standing by as jihadists expand their territory, recruitment and training. In Libya, the job of stemming an incipient civil war has been left to a feckless U.N. mediator, even though the Islamic State is known to be operating at least one training camp with hundreds of recruits. In Nigeria, where a new offensive by the Boko Haram movement has overrun much of one northeastern state, a U.S. military training program was recently canceled by the government following a dispute over arms sales.

The bankruptcy of U.S. policy toward the Syrian civil war was underlined again on Wednesday, when Secretary of State John F. Kerry expressed hope for a patently cynical and one-sided diplomatic initiative by Russia, which has been working to preserve the regime of Bashar Assad. It’s been nearly a year since the last U.S. diplomatic effort to end the war collapsed, and the administration continues to offer no strategy for how to stop the regime’s assaults on moderate Syrian forces it is counting on to fight the Islamic State. It has ignored widespread assessments that its program for training Syrian forces is too small and too slow.

The attacks in Paris were conducted by homegrown militants, but training and direction may have come from an al-Qaida affiliate in Yemen, which claimed credit Wednesday. There, too, a U.S. counterterrorism program once cited by Mr. Obama as a model is foundering: Iranian-backed rebels have overrun the capital and pushed aside the U.S.-backed government, making it difficult to continue direct and indirect U.S. operations against al-Qaida.

In a speech last May, Mr. Obama identified terrorism as the greatest threat to the country and noted the decentralization of al-Qaida to multiple theaters. Ruling out U.S. military involvement, he said his strategy would be to forge “a network of partnerships” with local forces and governments “from South Asia to the Sahel.” While the idea was mostly sound, the execution has been weak. There is, as a practical matter, no U.S. partnership in Libya, Nigeria or Syria. In other places, such as Iraq and Yemen, it is underpowered.

The president’s resistance to using U.S. military assets has also proved counterproductive. His refusal to provide even limited protection or heavy weapons to Syrian rebel forces has diverted many fighters to the better-funded Islamic State and other groups linked to al-Qaida. Mr. Obama’s rejection of proposals to deploy U.S. Special Operations forces with Iraqi army units is one reason Mosul and other cities remain under the jihadists’ rule.

The attacks in Paris should motivate Mr. Obama to reinvigorate a war against al-Qaida that appears to be dangerously stalled.