In a hastily organized meeting on the sidelines of the NATO summit meeting here, diplomats and defense officials from the United States, Britain, France, Australia, Canada, Germany, Turkey, Italy, Poland and Denmark conferred on what they called a two-pronged strategy: working to bolster allies on the ground in Iraq and Syria, while attacking Sunni militants from the air. They said the goal was to destroy the Islamist militant group, not to contain it…

An administration official on Friday said there were concrete reasons for assembling a coalition that went beyond the political cover that such an alliance might offer the president from a war-weary American public. For one thing, the official said, certain countries bring specific expertise, like Britain and Australia in special operations, Jordan in intelligence, Turkey in border control and Saudi Arabia in financing.

“Sure, the American military can handle airstrikes,” the official said, speaking on grounds of anonymity to discuss sensitive diplomatic and military negotiations. “But it’s always nice to have help from your friends.”