The most telling part of the statement is the blunt description of the situation in Bahrain, which if basically universally-acknowledged at this point is still notable coming from State. They write,
Bahrain has experienced a breakdown in law and order in various areas of the country over the last few weeks. Demonstrations have degenerated into violent clashes between police and protesters on several occasions, resulting in injuries. There also have been multiple reports of sectarian groups patrolling areas throughout Bahrain and establishing unofficial vehicle checkpoints. On March 14, 2011, foreign military elements entered Bahrain. Spontaneous demonstrations and violence can be expected throughout the country.
Update: The U.S. announcement makes even more sense now in light of the three-month state of emergency--or, as he calls it, a "state of national safety," which sounds so much better--just announced by King Hamad. Of course in the Arab world states of emergency have a way of being extended indefinitely.