The White House seems receptive. “Diplomacy in Syria, backed up by military threat, is a potential model for negotiations on Tehran’s nuclear ambitions,” U.S. President Barack Obama said Sunday. My view,” he continued, “is that if you have both a credible threat of force, combined with a rigorous diplomatic effort, that, in fact you can strike a deal.” He added later that that he would be willing to “test” Rouhani’s overtures.

Iran’s supreme leader, Ayatollah Ali Khamenei, too, has endorsed Rouhani’s efforts to “address diplomatic disputes with major world powers.” Obama and Rouhani have exchanged letters and both will speak at the U.N. General Assembly next week — and rumors are flying about a possible meeting between the two leaders.

This does not have to be a zero-sum game; Russia’s win does not have to be America’s loss. But playing for much higher stakes than in Syria, Obama ought to know what to expect from the “Syrian formula” that Putin is likely to reapply to Iran, lest he be blind-sided.

Russians play chess. U.S. leaders play golf. Looking at the geostrategic chessboard as Obama and Kerry were toing and froing on Syria, Putin saw a strategic opening wide enough to drag three rooks through – and he acted quickly. If he sees a similar opportunity with respect to Iran, the United States should watch out: As with Syria, Putin will open the door to a winding and slippery tunnel with not much light at the end of it. Whether it backs away from the door or steps over the threshold, one hopes that this time, the White House tread cautiously but confidently instead of being pushed into a fateful policy or stumbling into it.