the negative drawback is the rise in crude oil prices. OPEC members might raise the production to meet the world's demands to overwhelm the possible cut of production of oil in Iran. i expect that the prices of oil will rise because of investors who'll buy more oil in markets.
Iran might block the straight of Hormuz , but the question is for how long ?
i see that the US military in the Gulf will be able to end such blockade within few hours by quick air strikes.
so this leaves us at the sea mines problem.
4. By a curious twist of fate, Shiite populations sit over a considerable portion of the gulf's oil. Apart from Iran itself, and in southern Iraq, Saudi oil is in the North West, over the top of which sits a significantly sized Shiite populace, which supplies a good portion of the workforce. It has agitated a couple of times and had to be put down quite heavily (if need be i'll find my essay sources I wrote on a similar topic to back myself up). If Iran were to be attacked, it would not only be oil passing through the straits that would be in danger but the actual areas of production. It would require small encouragement from Iran to persuade them to cause trouble if it was perceived the only Shiite state were in peril. Woe to him that spits on the Ummah.
just a comment on what you have wrote for clarification:
- the Shiites population in Saudi Arabia exist in Al Qatif town which is the only Shiite town in all of Saudi Arabia and all of the Eastern Province , they are less than 5% of the population of KSA (and approximately less than 33% of the population of the eastern province) , most of this small population are farmers and traders but none of them belongs to ARAMCO nor have any access to the oil fields which are heavily guarded. not even Al Qaidah was able to penetrate it.
- the Shia themselves inside Al Qatif are of different rival sects and of different religious backgrounds , the murder of one of the judges in Al Qatif about a year ago have exposed this competition for us. very few of the Shia in Saudi Arabia would respond and support Iran because thats exactly whats happened in 80-88 war.
- Iran have carried out failed attempts to unify them and aquire their loyalty , this appeared through Al Sadr terror militia official who was arrested by the Security Forces during Hajj last year and seized several Safawi fundamental books and he was trying to set up a meeting with the Shiite leaders of Al Qatif to get this loyalty.
- there are 3 SANG brigades in the eastern province not far from Al Qatif.
- Saudi Arabia and other GCC's have the capability to respond in a similar way on Iranian soil by adopting and establishing Sunni militias to hit Iran's interests.
- Iran did carry out plenty of terror attacks against GCC before but most of them were failed and did not have any considerable effects.