Not really, no.
I don't see any one state launching a nuclear weapon at anyone, for it would be suicidal for that state. You could always argue perhaps that, one of the Islamic countries could have a loony leader and decide to make that country one big Martyr land in order to destroy their enemy, but it's not likely.
Don't get me wrong, I'm very cautious of the middle-east and asia.
Just not that particular scenario.
I very well doubt Iran will freely be able to equip themselves with a nuclear missle, or even if they did, I suspect they would not have it for long...
As for South Korea and Japan, who knows.... maybe.
Saudi Arabia- definately not. The US would be in a fit if they even said the word "nuclear".