Ditching the FSA will be easy because it barely exists these days, building an indigenous force … not so easy.

WASHINGTON — John Allen, the retired Marine general in charge of coordinating the U.S.-led coalition’s response to the Islamic State, confirmed Wednesday what Syrian rebel commanders have complained about for months: that the United States is ditching the old Free Syrian Army and building its own local ground force to use primarily in the fight against the Islamist extremists.

“At this point, there is not formal coordination with the FSA,” Allen told reporters at the State Department.

That was perhaps the bluntest answer yet to the question of how existing Syrian rebel forces might fit into the U.S. strategy to fight the Islamic State. Allen said the United States’ intent is to start from scratch in creating a home-grown, moderate counterweight to the Islamic State.

For most of the three years of the Syrian conflict, the U.S. ground game hinged on rebel militias that are loosely affiliated under the banner of the Free Syrian Army, or FSA. Their problems were no secret: a lack of cohesion, uneven fighting skills and frequent battlefield coordination with the al Qaida loyalists of the Nusra Front.

This time, Allen said, the United States and its allies will work to strengthen the political opposition and make sure it’s tied to “a credible field force” that will have undergone an intense vetting process.

“It’s not going to happen immediately,” Allen said. “We’re working to establish the training sites now, and we’ll ultimately go through a vetting process and beginning to bring the trainers and the fighters in to begin to build that force out.”