Sensible words about Iran and the bomb

Steven Walt looks at history and what has happened when other countries went nuclear.  He steps through several situations:

• Did the world turn on its axis when the mighty Soviet Union tested its first bomb in 1949?  
• Did British and French acquisition of nuclear weapons slow their decline as great powers?  
• Did China's detonation of a bomb in 1964 suddenly make them a superpower?
• Does Israel's nuclear arsenal allow it to coerce its neighbors or impose its will on Hezbollah or the Palestinians?
• India's "peaceful nuclear explosion" in 1974 didn't turn it into a global superpower, and its only real effect was to spur Pakistan -- which was already an avowed rival -- to get one too.
• North Korea is as annoying and weird as it has always been, but getting nuclear weapons didn't transform it from an economic basket case into a mighty regional power and didn't make it more inclined to misbehave.

He concludes

At bottom, the whole debate on Iran rests on the assumption that Iranian acquisition of a nuclear weapon would be an event of shattering geopolitical significance: On a par with Hitler's rise to power in Germany in 1933, the fall of France in 1940, the Sino-Soviet split, or the breakup of the former Soviet Union. 
Proliferation has not transformed weak states into influential global actors, has not given nuclear-armed states the ability to blackmail their neighbors or force them to kowtow, and it has not triggered far-reaching regional arms races. In short, fears that an Iranian bomb would transform regional or global politics have been greatly exaggerated; one might even say that they are just a lot of hooey.