Let's cut to the chase on the whole mess surrounding Iran. It is looking like a conflict in the Persian Gulf this spring/summer is becoming more of a possibility; the “crippling sanctions” the United States is trying to impose on Iran are leaky enough not to be “crippling”. India, China and Turkey are all balking at joining in on the isolation, which means that Iran is unlikely to just give up on their nuclear research program. That kicks the ball back into the court of the US/Israel, both of whom have insisted that Iran not be allowed to develop a nuclear weapon, and leaves US and Israeli leaders with two options: back down or follow through on their threats of military action.
The spectre of Iran with a nuclear weapon is driving the march to war, but what does Iran having a nuclear weapon really mean? So far there are several arguments as to why this is such a terrible idea that war would be necessary to prevent it, but taking a look at each argument shows that they are all fairly weak. Here they are, in no particular order:
A nuclear Iran is a threat to the United States. Not really. Consider that if Iran were to tomorrow announce that they had successfully built a nuclear bomb, the US arsenal would outmatch theirs by a factor of about 3,000-1. Even if Iran would decide to use this weapon and could deliver it to the United States (a big if), it would be a devastating attack, but not one that would destroy the country, not even close. Of course it would ensure a retaliatory strike that would destroy Iran. No country is suicidal, therefore this is not a real threat.
Iran might give the bomb to terrorists! It is an idea that makes for a great spy thriller, but one that makes no sense in real life. Do we really think Iran would spend billions of dollars, decades of research and turn themselves into a “rogue state” (at least according to the US) in pursuit of a nuclear bomb, only to give it to a terrorist? It makes no sense. Besides, if you want to worry about terrorists getting a bomb, then worry about them stealing one from Pakistan, where nuclear security is particularly weak, or buying one outright from North Korea.
The nuclear dominoes will fall. Saudi Arabia has said publicly that if Iran gets the bomb, they may be compelled to embark on their own nuclear weapons program. Of course the Saudis say a lot of things and in the past have threatened to start working on a bomb in response to Israel's nuclear arsenal, but never have. And even if the Saudis do start work on their own bomb, who will that be a threat to besides Iran?
A nuclear Iran is a threat to Israel. We're at least getting to the semi-plausible reasons here. Israel is a much smaller country that the United States, so a much smaller nuclear strike could be devastating to them. But the Israelis are keenly aware of this and will have prepared a second-strike capability (the ability to retaliate if hit without warning). Israel's nuclear arsenal is somewhere between 200-400 weapons, meaning that they could likely hurt Iran a lot worse than Iran could hurt them, which makes an Iranian first strike highly unlikely.
That leaves us with something I'll call the Yom Kippur Scenario. In 1973 Israel fought its last great war when a coalition of Arab states launched a surprise attack during the Jewish holiday of Yom Kippur. Part of the Arab motivation was revenge for the solid defeat they had suffered in 1967 during the Six-Day War. The Yom Kippur War started badly for the Israelis, for awhile it seemed as though the Arab forces might be victorious, before Israel rallied and pushed the Arabs back crossing into both Egypt and Syria in the process.
Israel has never forgotten this lesson. The Israeli nuclear arsenal is to ensure that such a scenario does not again occur. Basically, if there were to be a repeat of the Yom Kippur War, and if this time Israel were about to be defeated by a coalition of Arab states, they could use their nuclear arsenal to devastate the lands of their attackers, giving the Arabs a true Pyrrhic Victory. Israel has made this intention clear to their Arab neighbors, and it is an effective deterrent - so long as no one else in the neighborhood has their own nuclear arsenal. Iranian bombs, and the ability to deliver them, changes this equation, and robs Israel of this deterrent.
Of course a second Yom Kippur War is highly unlikely. Israel has had calm, if not cordial, relationships with their neighbors for 40 years now. The Israeli military is by far the most powerful and most capable in the region, since the militaries of most of their neighbors are designed to suppress domestic unrest rather than to campaign beyond their borders. Yet this is the real motivation for the current standoff with Iran: to prevent a challenge to Israel's military hegemony in the region.
But is this justification for a conflict that will cause upheaval across the region and be a severe blow to an already shaky global economy? That is the question that we should be discussing.