But the White House says it is not to blame. The finger, it says, should be pointed not at Mr. Obama but at those who pressed him to attempt training Syrian rebels in the first place — a group that, in addition to congressional Republicans, happened to include former Secretary of State Hillary Rodham Clinton.

At briefings this week after the disclosure of the paltry results, Josh Earnest, the White House press secretary, repeatedly noted that Mr. Obama always had been a skeptic of training Syrian rebels. The military was correct in concluding that “this was a more difficult endeavor than we assumed and that we need to make some changes to that program,” Mr. Earnest said. “But I think it’s also time for our critics to ‘fess up in this regard as well. They were wrong.”

In effect, Mr. Obama is arguing that he reluctantly went along with those who said it was the way to combat the Islamic State, but that he never wanted to do it and has now has been vindicated in his original judgment. The I-told-you-so argument, of course, assumes that the idea of training rebels itself was flawed and not that it was started too late and executed ineffectively, as critics maintain.