It is interesting to see the map below of Middle East, its Shia population and major oil fields. Perhaps it explains why Saudi Arabia, and may be even West, is extremely concerned about any Shia uprising or Shia as predominant force in Middle East. Red areas are oil fields, Green areas are Shia population. Although there are no oil fields next to Yemen shia population, but uprising there can inspire the Shia in East, next to Bahrain. It also explains why Saudi Arabi sent tanks to Bahrain, perhaps with green light from West, during uprising two years ago, and war in Yemen. Is this a self created sectarian war for control of oil?

Map below is of Middle East , red is Gas fields, Black oil fields. Read description in the map for details of population.

Geocurrents map.