The Obama administration is quietly working with Saudi Arabia and other Persian Gulf allies to speed up arms sales and rapidly upgrade defenses for oil terminals and other key infrastructure in a bid to thwart future military attacks by Iran, according to former and current U.S. and Middle Eastern government officials.

The initiatives, including a U.S.-backed plan to triple the size of a 10,000-man protection force in Saudi Arabia, are part of a broader push that includes unprecedented coordination of air defenses and expanded joint exercises between the U.S. and Arab militaries, the officials said. All appear to be aimed at increasing pressure on Tehran.

The efforts build on commitments by the George W. Bush administration to sell warplanes and antimissile systems to friendly Arab states to counter Iran’s growing conventional arsenal. The United Arab Emirates and Saudi Arabia are leading a regionwide military buildup that has resulted in more than $25 billion in U.S. arms purchases in the past two years alone.