Why is a Nuclear Iran Worse than a Nuclear Pakistan or North Korea?

An "old soldier" takes to Tom Ricks' blog to ask a good question:

Why is a nuclear armed Iran unacceptable, when an already nuclear-armed North Korea and Pakistan are? 

In order to buy into the Iran exception (the other two being the rule, and now India, a third, has morphed into a rule maker) you have to believe that Iran is perfidious and powerful. The former is true, and the latter is not. Iran is also not crazy or eager for the end of the world.  Watch what they do, not what they say. 

Israel has a nuclear monopoly.  They are deluded into thinking that they can keep this monopoly permanently. The GoI  also has to brush up on the theory of deterrence.  It worked for the U.S. and USSR, it works for China and the U.S., and it will work for Israel and Iran -- especially because Iran is not crazy. 

A nuclear Iran is not good, and not preferable, but it is not the end of the world.  To bomb makes little sense and may be the policy equivalent of committing suicide out of the fear of death. 

Since retired officers usually identify themselves when the write for Ricks, we can assume that this officer is still on active duty. Ricks has his finger on the pulse of the U.S. officer corps -- at least in the Army and Marines -- and they do not want a war.