Shiites have long been an oppressed minority on the Arabian Peninsula; though a disproportionately large portion of the known oil deposits is drawn from their land. The northern Saudi oil, Bahrain are notable, and it looks like the oil producing part of Yemen as well.

Knowing that the Brits had Iranian oil cornered when the US made a move on Arab oil; I would not be surprised if this influenced our perspectives as to who to throw our lot in with. To elevate Shiite leadership may have been seen as too likely to fall under Britiish influence.

This is a division we could play to our advantage today, both to help stabilize and reduce the strategic significance of the Saudis; and also to open better lines of communication with the Iranians. Both of those are vital US interests.

The Gulf States sending security forces understand this very well, and those leaders are acting far more to sustain their own status quo than they are to ensure there are no temporary disruptions of oil flow. Temporary they can live with; but the creation of 1-2 Shiite states on the AP? I suspect that makes them very nervous indeed.

Next thing you know the Hashemites will re-exert their claim on leadership of the region...