Any power which can exert influence in Persian gulf will control the oil futures of these countries - no doubt about that.
The Iranian hostility emerges from the Arab alignment with Americans for security in the Persian Gulf - a failure of Irans own Ayatollah obession who have taken the path of arrogance rather than dialogue, mutual respect and co-operation. Iranian arrogance is a suicide for both as long as oil futures are concerned. Since the removal of Saddam - the US naval fleet has no excuse to stay in the Persian gulf lest they stir the pot of Iranian threats day and night.
On the other side it is pathetic to see how Arab leaders soil their thoobs just by the name of Iran and take desperate measures...their worst fear is influence of Persian culture when they have already borrowed heavily from Persia - which has been a great patron of sciences, arts, civilization, architecture and human values but have no problems in opening their air waves to lewd western values and emulating them as well.
The khalifas have been exploiting religious differences for political legitimacy but in any scenario like this - sh_t is ought to hit the fan sooner or later. One simply cannot go against the majority. And for this reason, the GCC merger talks have already failed. GCC is an artificial entity which can only survive as a trade model on the lines of EU..but the ethnic and cultural differences are too vast to advocate a merger.
I just wish the peace, stability and prosperity of KSA should not come under threat of war..it will be a heavy blow and reverse all the gains of last seven years of development.