must disagree. It is pretty much accepted in military circles That "one flies, they all fly". If, say Israel hits Iran, Pakistan, fearing the loss of the few nukes they have, will lob them at India and vice versa. With all the nukes flying around, China will probably decide that it's a good time to take care of the "Taiwan problem". etc, etc, etc until all the nuclear powers are involved.

I don't know what military circles you ran in but the ones in my experience said no such thing. In fact, during the Cold War, there were people on both sides who believed that tactical nuclear warfare was very possible. They developed short range missiles and even artillery shells with nuclear warheads as well as small bombs that could be dropped from tactical aircraft such as the F-105. They didn't believe that a single detonation would lead to all out nuclear war.

As an example, suppose Iran developed a bomb and carries through on it's pledge to use it on Israel. Israel will most definitely counterattack - HARD. Why would that make Pakistan hit India knowing India will respond in kind? Pakistan and India pushed pretty close to the brink several years ago but when they looked into the abyss, they didn't like the view. Since then, both sides have sobered up and the tensions are much less.