DUBAI (Reuters) - The United States and its allies have launched a major naval exercise in the Gulf that they say shows a global will to keep oil shipping lanes open as Israel and Iran trade threats of war.
Publicly announced in July, the operation, known as IMCMEX-12, focuses on clearing mines that Tehran, or guerrilla groups, might deploy to disrupt tanker traffic, notably in the Strait of Hormuz, between Iran and the Arabian peninsula.
The start of the event, with a symposium for officers from more than 30 navies, came as Israeli Prime Minister Benjamin Netanyahu told U.S. television viewers on Sunday that Tehran was close to being able to build a nuclear bomb; his words fuelled talk of an Israeli strike, and of Netanyahu pressuring President Barack Obama to back Israel as Obama battles for re-election.
Military officials, diplomats and analysts - as well as Iran itself - all sought to play down the significance of the timing and to stress the defensive and hypothetical aspects of the exercise, which moves on to the water from Thursday with ships from a much smaller number of nations taking part in maneuvers.
However, it was a clearly deliberate demonstration of the determination on the part of a broad coalition of states to counter any attempt Iran might make to disrupt Gulf shipping in response to an Israeli or U.S. strike on its nuclear facilities - a form of retaliation Iran has repeatedly threatened.
"This exercise is about mines and the international effort to clear them," Vice Admiral John Miller, commander of the U.S. Naval Forces Central Command, told officers assembled for the symposium at his fleet headquarters in Bahrain on Monday.
"Represented here are the best of our individual countries' efforts dedicated to securing the global maritime commons."
As well as Britain and France, the main European naval powers, a number of Middle Eastern states are taking part, along with countries from as far apart as Estonia and New Zealand.
"The demining efforts are clearly in preparation for a showdown with Iran," said Hayat Alvi of the U.S. Naval War College, "Presumably in the context of either an Israeli strike targeting Iran's nuclear facilities, or some provocation that leads to an Iranian response in the Persian Gulf region."
U.S. forces in the Gulf include two aircraft carriers on permanent station, though these will not take part in the latest exercise - one of dozens held by the fleet every year. For its part, Iran has said it will hold a major air defense exercise next month, showing its ability to protect nuclear sites.
Western powers are also involved in planning a major naval exercise to be held in the eastern Mediterranean next month.
Netanyahu's comments on U.S. television on the potential progress Iran might make over the next few months in enriching uranium towards the point where it would be useable in a weapon were short on detail but stressed the notion that Tehran was on the brink of a major breakthrough which Israel would not accept.
Obama, who has faced criticism from Republican challenger Mitt Romney of being too soft on Iran and too hard on Israel, has stressed a desire to give international economic sanctions and diplomacy time to persuade Tehran to change tack on a nuclear strategy it says is intended only for civilian purposes.
Catherine Ashton, the European Union foreign policy chief who is leading international efforts to persuade Iran to accept checks and limits on its nuclear work, will meet the chief Iranian negotiator Saeed Jalili in Istanbul on Tuesday, officials announced on Monday. The encounter follows a renewed round of discussions begun in May after over year of stalemate.
With strains showing between Israel and Washington, German Chancellor Angela Merkel, a powerful ally to both, said on Monday that she believed a peaceful outcome was still possible, despite skepticism from Netanyahu that diplomacy will work.
"Iran is not just a threat to Israel but for the whole world," Merkel told a news conference, in remarks that echo an element of Israel's arguments. "I want a political solution and think we should act together internationally, and I believe that the room for a political solution has not been exhausted."
The heat of the dispute was in evidence in Vienna, where the U.N. nuclear supervisor, the IAEA, held its annual meeting. An Iranian representative drew a link between an explosion which cut power to a uranium enrichment plant last month and a visit by U.N. inspectors. Suggesting "terrorists and saboteurs" may have infiltrated the agency, his comments recalled speculation that Western or Israeli agents have already made covert attacks.
Oil prices were little changed on Monday, though tensions have spooked markets before. Iranian threats to block the waterway through which about 17 million barrels a day sailed in 2011 have grown as U.S. and European sanctions aimed at starving Tehran of funds for its nuclear program have tightened.
But Iranian military officials sounded a relaxed note, reassuring their own public: "This exercise is a defensive exercise and we don't perceive any threats from it," said Mohammad Ali Jafari, commander of the Islamic Revolutionary Guard Corps. "We are not conducting exercises in response."
Anthony Skinner of the Maplecroft consultancy said the exercise would, however, remind Iran of Washington's ability to blunt its offensive capabilities: "Iran would likely mine the Strait of Hormuz and possibly deploy suicide bombing skiffs in the event of air strikes against its nuclear facilities.
"Washington wants to show that it's prepared for such an eventuality," Skinner said. "I see this exercise as part of broader initiative to sustain the pressure on Iran. Giving sanctions the time to work is clearly the preferred option for the Obama administration, at least in the medium term."
Meir Javedanfar, an Iranian expert in Israel, suggested that publicity for the exercise was primarily aimed at American voters and the Israeli leadership: "This military exercise is Obama's way of showing U.S. voters, especially Israel's supporters in the U.S., and Netanyahu that when it comes to Iran, he is not only relying on talks," he said. "To show that when he said 'I have Israel's back' in March ... he meant it."
In a statement, the U.S. navy recalled what it described as terrorist attacks in 2002 on the French tanker Limburg off Yemen and in 2010 on the Japanese M. Star in the Strait of Hormuz, as examples of the "hypothetical threat" to shipping in the area of the exercise, which would take place at sea in three areas, two in the Gulf and one at the mouth of the Red Sea.
Western navies have also been practicing in recent years how to respond to small, fast boats, possibly crewed by suicidal assailants, which could target larger ships in the way the U.S. destroyer Cole was damaged in a Yemeni port 12 years ago.
Additional reporting by Yeganeh Torbati and Marcus George; Writing by Alastair Macdonald; Editing by David Stamp