Latest killing raises pressure on Iran's regime

For Tehran's neighbours, the assassination of an Iranian nuclear scientists could not have come at a worse time. Only a player eager to see Iran fighting the US would welcome this new higher peak of tension.

The bomb that killed Iranian nuclear scientist Mostafa Ahamdi Roshan on Wednesday was not very big, as photos of his mostly-undamaged auto reveal. But the murderously efficient device may have moved the world closer to a vastly bigger blow-up, because it came at a time when Iran's unpredictable government is on edge.

Iranian officials and diplomats wasted no time in blaming the US and Israel. The Americans issued a denial; the Israelis were blandly silent. Certainly somebody is systematically attacking Iran's nuclear programme; no actuary would believe that so many killings, bombings, and computer disasters are mere bad luck.

This case, though, maybe is different from the previous ones. In recent weeks Iran has become more than ever a pariah state, as economic sanctions cut the country off, slowly but relentlessly, from the world economy. Reacting to impending sanctions with imprudent military bluster, Iran threatened to close the Strait of Hormuz.

Shippers, and their insurers, know that only a few maritime mines could choke off much of the world's crude-oil flow. Several governments, most importantly the one in Washington, reacted to that by calmly citing international maritime law. The Americans also dispatched a second aircraft-carrier battle group to the region.

The latest assassination, then, risks intensifying the drumbeat of pressure on Iran. The danger now is that the government there, a strange mixture of clerical, political and military power centres often apparently at odds with each other, could do something frantic or irrational.

From the point of view of Iran's neighbours, then, the timing of this killing was awful. Only a player eager to see Iran fighting the US would welcome this new higher peak of tension.

Even without the killing however, the world community has for months been backing Iran forcefully into a corner because of its unwise ambiguity about its nuclear ambitions.

A rational regime would by now have abandoned this opacity and forsworn nuclear weapons. Nobody wants a bomb in the region, but the danger is that those who keep tightening the screws are also expecting a rational response from Tehran.

It remains to be seen if that is itself a reasonable expectation.