I may differ with you.. you are underestimating iran capacities.. if usa withdraw its forces from iraq it is big win for iran...one General death is not big price...if they dont then usa will face lots of problem in Gulf of Persia iraq and most impotan is isreal security is in deap danger.. Gulf of Persia hold 70% oil route.. you know what does that mean to world..
Iran has already said that it will respond militarily. The US leaving Iraq, which actually seems more and more unlikely now, wouldn't change anything.
As for Israel, if Iran attacked Israel, Iran would have to deal with an Israeli counter attack, not a US one.
Finally, blocking the Strait of Hormuz would turn even Iran's allies into enemies, including its immediate neighbors. China, and India rely on the strait heavily, as well, Pakistan (Iran's immediate neighbor) would face another (far more severe) energy crisis, and consider the blockade a threat to its national security.
Blocking the strait is only a good idea if
A) Iran is okay with turning its neighbors into enemies.
B) If it faces immediate threats of invasion by foreign forces.
In the end, I wouldn't recommend it.
UN is international territory. The US can deny Iran airspace into reaching the UN HQ, but the US cannot annex the US HQ as US territory.
While technically, the US has an obligation to allow even diplomats from enemy nations to attend the UN, the US doesn't have to allow those same diplomats from entering US territory itself to get to the UN venue.
This is why I've always thought a neutral country (like switzerland) would be a better location for the venue hosting the United nations.