Actually, no, it's a terrible buffer. Normally, the Persians and Arabs have no real love for each other. The Arabs are Sunnis, the Persians are Shi'ites. They've been fighting each other since the death of Mohammed's heirs.
Yes, the Iranians HAVE gained power in Iraq, Syria and Lebanon- all countries with large Shi'ite communities, and where the US and Israel have weakened the states they had.
Sounds like you want to blame Iran for our fuckups.
Sure, I can. the rest of those things are minor. the problem with Empires is that they are temporary. Empires rise, Empires fall, the people go on. Since the Romans dispersed the Jews in the second century, Palestine has been part of the Roman, Byzantine, Sassanid, Rashidun, Umayid, Abbasid, Fatamid, Crusader States, Ayubbid, Ottoman and British Empires. The people remained... pretty much the same. Until the Zionist squatters started pushing them off their land.
Wait, isn't this what you fuckwads said about Iraq 20 years ago. We take care of Saddam, everyone will love the Zionist Entity?
Clean Break Strategy was all for the US attacking Iraq and destabilizing Syria.