The description by Robert Kagan of the president’s new toughness (that might hopefully intimidate the Iranians) is intriguing because it follows a series of not necessarily coincidental warnings from Americans to the mullahs starting in July.

First, Leon E. Panetta, director of the Central Intelligence Agency, said that new sanctions would probably not be sufficient to back Iran away from its nuclear weapons drive. A predecessor as C.I.A. chief, Michael V. Hayden, then described the likelihood of a military strike on Iran as rising, and suggested it might not be the worst “of all possible outcomes.”

When Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, was subsequently asked whether the United States had an attack plan for Iran, he replied, for the first time, “We do.” Add to this list an article by Bruce O. Riedel, another former C.I.A. officer, with ongoing ties to the agency, arguing that Washington ought to act now and sell Israel nuclear powered submarines with missile capabilities.

The problem with evaluating the tough talk, which preceded Mr. Obama’s meeting with the writers, was that nothing was reported among the president’s comments to match it in substance or tonality.

I asked George Perkovich, vice president for studies and director for nuclear policy at the Carnegie Endowment for International Peace, how real or effective the seemingly combative diction sounded to him.

His answer: these attempts “have no effect on Iran. It appears to me that this is done less to scare Iran than to silence critics on talk radio here in America. It would be desirable for the United States to have credible use of force in relation to Iran, but in my view we do not.”

So what to think of the version of Mr. Obama’s August conversation that has him putting talks with Iran firmly back on the table? I have talked to people who say the Americans are testing out possible new approaches to Iran in informal contacts with friends outside the United States.