Days after a State of the Union address that threatened "growing consequences" if Iran continues to ignore international concerns over its nuclear programme, the Obama administration has quietly revealed plans to increase its military presence and step up arms sales to friendly regimes in the Persian Gulf.
The US will provide new anti-missile systems to at least four Arab countries, and help Saudi Arabia triple the size of a 10,000-man force protecting its most important potential military targets from attack. America's Navy will also begin deploying ships capable of intercepting medium-range nuclear missiles off the Iranian coast at all times.
News of the moves slipped out in a mixture of off-the-record interviews and formal briefings over the weekend, and is likely to fuel concerns of an arms race among mutually suspicious regimes in the region. The United Arab Emirates and Saudi Arabia have spent at least $25 billion [£15.6bn] on US-built weapons in the past two years.
For President Obama they represent a tangible shift in policy: in contrast with President Bush, he had until now hoped that quiet diplomacy might persuade Iran to rein back its nuclear programmes. However, his early efforts to make overtures towards Tehran have fallen flat and international inspectors have yet to be granted access to the country's nuclear development facilities.
That appears to have prompted the new, tougher line from the Obama administration. "As Iran's leaders continue to ignore their obligations, there should be no doubt: they, too, will face growing consequences," said the President, in his State of the Union address last week.
Iran continues to insist that its nuclear ambitions are civilian rather than military. After meeting allies in London last week, Secretary of State Hillary Clinton told reporters that the US now hopes to convince the international community to increase sanctions against its government, and warned China that its opposition to that move was "short-sighted."
In an effort to sidestep allegations of warmongering, the Obama administration is eager to stress that all of its new deployments are entirely defensive in nature. They form part of an updated global ballistic missile defence policy that will be put to Congress today.
Outlining some details of the new US policy, General David Petraeus, the Central Command chief responsible for the Middle East, told a conference at the Institute for the Study of War in Washington that new systems being supplied to the region consisted of "eight Patriot missile batteries, two in each of four countries".
Those countries are thought to be Qatar, Kuwait, the UAE and Bahrain, which will join Saudi Arabia and Israel in possessing the equipment. Adding that Patriots are capable of shooting down short-range offensive missiles, General Petraeus said: "Iran is clearly seen as a very serious threat by those on the other side of the Gulf front."
He also revealed that the United States Navy
will now be keeping Aegis cruisers on patrol in the Persian Gulf at all times, vessels which are generally equipped with radar systems that are designed to intercept medium-range missiles.
Accepting US military support can present political problems for Arab countries, and the White House did not formally comment on any of the moves.