Barack Obama didn't sound exactly sanguine as he spoke with Bibi Netanyahu about the atomic threat that Iran poses to neighbors near and nearer. But he seems to grasp that Tehran may not think the U.S. serious in its determination to prevent the Ayatollahs from going nuclear.

Here's what the president said: "We are not foreclosing a range of steps including much stronger international sanctions in assuring that Iran understands that we are serious." Now, if the mullahs somehow have missed the point, where does responsibility lie?

It lies, first of all, in the very nature of international sanctions.

Since they have to be non-porous--o.k., relatively non-porous--the provisions of a boycott would have to be approved at the Security Council without veto by any of the five permanent members. The shadow of a veto (or vetoes) is what has kept all previous decisions United Nations-toothless. This is a particular form of bombast with no energy beyond it. The very fact that Obama is still alluding to "much stronger" sanctions testifies to the puffery of the threat, that is, to its virtual irrelevance.

And what does the president mean by "the range of steps" of which sanctioning is only one?

Of course, he also intends to continue to talk with the Iranians directly. This is no sin. Moreover, he has chosen as his negotiator the strong and supple Dennis Ross who has on his record the clear ability to read the bad news into his estimates of what is possible.

And impossible. Read Ross' memoir of his time as a "peace processor" between Israel and the Palestinians, The Missing Peace: The Inside Story Of The Fight For Middle East Peace, to see what I mean.

To his credit, the president has made abundantly clear that talk cannot go on forever, a stipulation that would be more effective if conditions were set for the Iranians as cost of our participation.

But Dr. A'jad has long ago rejected any price of entry. So we are stuck. Still, the end of the year seems to be Obama's timeline. If that's what he truly means, the talk won't be like bargaining in the Isfahan market. Another glass of tea, please.

Up to now, Iran's nuclear ambitions have been seen primarily as a threat to Israel. And it's exactly what the regime intends. Of course, historically and religiously, the Shi'a state is at war with most of its Sunni neighbors... and they with it. Not, in the immediate future, a war fought by armies and aircraft. But there were already rivers of blood that ran between Iraq and Iran a quarter century ago, and that was its portent. No, the Arab states won't fight; the king of Saudi Arabia who is the sharif of Mecca and Medina and the protector of the faithful blah, blah, blah will summon the heads of other states in the Arab League for talk. And talk they will. And otherwise pray that Israel does what is also required for them. As Menachem Begin did it for them at Osirak in 1981.

But the contours of the nuclear contest do not just revolve around the Tehran-Jerusalem axis. There is also the nightmare of what occurs east of Tehran in Pakistan. A New York Times dispatch by David E. Sanger and Tom Shanker a few days ago. Actually, it is already occurring. Here are the mysterious essentials. Nobody actually knows how many actual nukes and ancillary nukes Pakistan possesses. Certainly not the U.S.

Or where they are. And how many are being made right now. Moreover, since the government is not exactly one rational actor, which of the many Pakistan factions has access to them. And what about Paki allies of the Taliban?

Maybe Tehran is building atomic weapons for its Shi'a millennial war against the Sunni. And perhaps, aside from the Hindu population next door in the resilient democratic state of India, it is the Shi'a who also figure in the practical calculations and macabre imaginations of Dr. Khan and his heirs.

Deterrence anyone?