I think World War III is unlikely. Confronted with the prospect of nuclear war, I think the west would sacrifice Israel, surrender and disarm. Better red than dead would be narrative of the day.
Israel is just a means to an end. It won’t stop with getting rid of Israel. That’s like saying giving Hitler the Sudetenland would have stopped him.
Israel would likewise sacrifice its allies to preserve itself.
That's what normal nations do. Only Western Europe and the Anglosphere is bent on self-destruction.
IAE, Israel has nukes. Taiwan will be "sacrificed" long before Israel.
I do not see any possibility of a “world war” - even if all of European NATO countries enter a war with Russia, I do not see China or India entering this war as it gains them NOTHING to intervene, but EVERYTHING to see Russia weakened and selling them cheaper oil.
Iran’s gov may want to take on Israel, but they know that they can’t without support from Turkey and Egypt and Saudia - and that’s not going to happen.
China wants Taiwan, but not that badly.
India distrusts China so any PRC move against RoC would be looked at askance.