It's all of those, yet none are the real root reason.

For that, you must look at the main beneficiary. Which country stands to gain the most from a completely dilapidated Iran? Which country stands to gain more when all the regional powers that could stand up to it have been destroyed?

I think the answer should be blindingly obvious.

It shouldn't take a genius to figure out that Christians and Jews don't like Muslims and Muslims don't like Christians or Jews.

Just look at the Sudanese conflict.