The main affect on the U.S. footprint in the region is that Bahrain is a Sunni-ruled kingdom that is home to the U.S. Navy’s 5th Fleet.  The U.S. Navy’s 5th Fleet has the responsibilities that include patrolling the busy waters off Iran.

“Two Bahraini policemen were wounded and six were injured in a bomb attack south of the island kingdom’s capital on Tuesday, according to authorities.”

“The blast was the latest in a series of bombings in recent years targeting security forces in the Gulf nation, which continues to face low-level unrest more than four years after protesters took to the streets to demand greater political rights.”
“The Interior Ministry described the bombing as a “terror blast,” and said it took place in the largely Shiite community of Sitra, just south of the capital, Manama. One of the wounded officers sustained serious injuries, the ministry said.”
“Bahrain is a Sunni-ruled kingdom that is home to the U.S. Navy’s 5th Fleet, whose responsibilities include patrolling the busy waters off Iran.” (Coordination Cell)

http://abcnews.go.com/International/wireStory/bahrain-makes-multiple-arrests-wake-deadly-bombing-32751752