The USSR, arguably, could cripple enough of our assets to make a first strike survivable (for them).
This, Iran cannot do. Not now, not ever.
Now, I'm one who doesn't buy the idea that Iran is led by crazy people who would welcome massive US nuclear retaliation for an attack against a soft target. I view the things that grow in Saudi Arabia as a much bigger threat.
But, I could obviously be wrong.>
But I stand by my original statement: "The acquisition of nuclear weapons by Iran is not a threat TO OUR NUCLEAR DETERRENT".
You are specifically correct...
I was not clear...
IMHO, Iran is a greater (defined as "more probable") uncontrolled threat to this country than either Russia or China... As is NK...