Paul Pillar writes: The killing of an individual foreigner overseas, if carried out for a political or policy purpose by either a nonstate actor or clandestine agents of a state, is an act of international terrorism. At least that is how U.S. law defines it, for purposes such as the State Department’s annual reports on terrorism. This form of terrorism is part of what put Iran on the list of state sponsors of terrorism. Through the 1980s and into the 1990s, the Iranian regime perpetrated numerous assassinations of exiled Iranian political dissidents, in Europe as well as in other countries of southwest Asia. The Iranians effectively ended this assassination campaign about a decade and a half ago, largely to improve relations with the European countries on whose soil many of the assassinations occurred and perhaps also because by then Iran had bumped off nearly all of the people on its hit list. We should assume, however, that Iran retains the capability to assassinate far-flung targets again, and that it would consider doing so if searching for ways to strike back at adversaries that are striking it.

Iran itself has been a victim of this form of terrorist violence. This has included some instances, such as the killing of Iranian diplomats in Afghanistan, in which Iranian interests have paralleled those of the United States. It has included during the past two years the killing in Iran of several nuclear scientists, the most recent of whom died this week from an explosive placed on his vehicle. Actions are more important than nomenclature, so if you prefer not to apply the T-word to these killings then just imagine what the reaction would be if something similar were occurring in the United States. Imagine the response if even just one scientist (let alone four or five) who was employed, say, at one of the U.S. national laboratories had been been similarly assassinated and a foreign hand was suspected. There would be screams of “act of war” and the U.S. president would be hard-pressed to hold back impulses to strike back forcefully. Now put yourselves in the Iranians’ place. Not only do they face the serial assassination of their scientists, but they face it amid an environment filled with numerous other indications of foreign hostility, including the economic warfare, the saber rattling and the contest among American politicians to see who can shoot the most rhetorical venom at Iran. From this perspective, aptly described by Vali Nasr, it should hardly be surprising if Iran strikes back while it sees more reason than ever before to develop a nuclear weapon in the hope of deterring U.S.-led aggressiveness.

A former senior Israeli security official tells the New York Times that uncertainty about who was responsible for the latest assassination is useful. “It’s not enough to guess,” he says. “You can’t prove it, so you can’t retaliate. When it’s very, very clear who’s behind an attack, the world behaves differently.”

How true that might be really depends on the form of retaliation. As Nasr and Pillar note, the rationale for Iran to want nuclear weapons in order to deter foreign aggression, has never been more compelling. So why should Tehran slow itself down in pursuit of that goal by allowing itself to rise to an Israeli bait?

Indeed, the longer Iran exercises restraint and the more reckless Israeli antagonism becomes, the more reason there is to ask: whose nuclear weapons in the Middle East should we fear the most?

Israel maintains a policy of nuclear ambiguity, which is to say that although it has a nuclear arsenal estimated to include as many as 400 weapons, it refuses to accept the international treaty obligations imposed on most other nuclear powers. Moreover, according to some observers it has its own version of “mutually assured destruction”. Unlike the original MAD doctrine which constrained the Soviet Union and the United States, Israel has the “Samson Option,” which is to say Israel won’t allow itself to go down without destroying human civilization in the process.

This is how Professor David Perlmutter articulated this apocalyptic vision ten years ago:

Israel has been building nuclear weapons for 30 years. The Jews understand what passive and powerless acceptance of doom has meant for them in the past, and they have ensured against it. Masada was not an example to follow — it hurt the Romans not a whit, but Sampson in Gaza? With an H-bomb? What would serve the Jew-hating world better in repayment for thousands of years of massacres but a Nuclear Winter. Or invite all those tut-tutting European statesmen and peace activists to join us in the ovens?

For the first time in history, a people facing extermination while the world either cackles or looks away — unlike the Armenians, Tibetans, World War II European Jews or Rwandans — have the power to destroy the world. The ultimate justice?

That might be the ultimate justice if everyone on the planet posed a threat to Israel, but Israel’s enemies are in truth far less numerous. So really, the image being evoked here is not one of justice but of the ultimate form of vengeance.

Individuals and nations can be at their most dangerous when cornered. As Israel continues its slide away from democratic principles and becomes increasingly strident in asserting itself as a Jewish theocratic state, the world has more reason to fear a nuclear threat in the Middle East that does not lurk somewhere over the horizon but is already a clear and present danger.

Avner Cohen, author of Israel and the Bomb and The Worst-Kept Secret: Israel’s Bargain with the Bomb, is the foremost scholar on the subject of Israel’s policy of nuclear ambiguity, and as he notes, Israel’s nuclear arsenal is only of value if Israel can remain the sole nuclear power in the Middle East.

On the one hand, the bomb’s purpose was clear: Ben-Gurion, who remained so helpless throughout the Holocaust period, wanted an ‘insurance policy’ to protect against a recurrence of such a tragedy. If you have the capability of threatening Hiroshima, you stave off Auschwitz. On the other hand, the other side could try to attain the same status. And if it were to succeed, then, suddenly, all of the calculations would be altered, moving from one extreme to the other. This was not like the Americans and the Russians, who found themselves more or less in a situation of parity. When both sides in the Arab-Israeli dispute have the bomb, Israel is trapped in an awful situation, worse than at the starting point. Thus, Israel’s real interest is for nobody to have the bomb.

Yet rather than pursue that goal of regional disarmament and the creation of a nuclear-weapon-free Middle East, those who are gunning for a war against Iran only have one ambition: that Israel must retain its regional military dominance.