".. Saudi intervention in Bahrain is a slap in the face of the US & a setback for peace on the island...

"... For the United States, the intervention is a slap in the face. On Saturday, March 12, U.S. Defense Secretary Robert Gates visited Bahrain, where he called for real reforms to the country's political system and criticized "baby steps," which he said would be insufficient to defuse the crisis. The Saudis were called in within a few hours of Gates's departure, however, showing their disdain for his efforts to reach a negotiated solution. By acting so soon after Gates's visit, Saudi Arabia has made the United States look at best irrelevant to events in Bahrain, and from the Shiite opposition's point of view, even complicit in the Saudi military intervention.
The number of foreign troop is so far very small and should not make one iota of difference in Bahrain's balance of power. The Bahraini military already total 30,000 troops, all of whom are Sunnis. They are under control of Crown Prince Salman bin Hamad al-Khalifa and supposedly fully faithful to King Hamad bin Isa al-Khalifa. Bahrain also has a similar number of police and general security forces, mainly mercenaries from Baluchistan, Yemen, and Syria, reputed to be controlled by the prime minister and his followers in the family.
At this time, therefore, the Saudi intervention is largely a symbolic maneuver. It is so far not an effort to quell the unrest, but intended to scare the more extreme Shiite groups into allowing negotiations.... The Saudi move, however, risks backfiring. It is extremely unlikely that the Saudi troops' presence will entice moderate Shiite and Sunni opposition figures to come to the table -- the intervention will force them to harden their position for fear of being seen as Saudi stooges. The demands of the more extreme groups, such as the Shiite al-Haq party, are also likely to increase prior to negotiations. These elements, having seen job opportunities go to foreign workers and political power dominated by the ruling family for decades, have grown steadily disenchanted with prospects of talks..."