By David Brunnstrom
WASHINGTON, July 27 (Reuters) - If evacuating U.S. embassy staff from Libya was perilous - three F-16 fighters and Marines in Osprey aircraft flew overhead a road convoy from Tripoli to Tunisia - sending them back in could be politically hazardous for President Barack Obama.
U.S. diplomats work in dangerous places such as Baghdad and Kabul, but the ghosts of Benghazi hang over the U.S. presence in Libya after an attack on a U.S. mission in the eastern Libyan city in 2012 that killed Ambassador Chris Stevens and three other Americans.
Republicans, preparing to battle Obama's Democrats in mid-term elections in November, have been quick to characterize the chaos in Libya as further evidence of the administration's weak foreign policy.
The eight or so U.S. diplomats who had been in Libya and a security staff numbering 200 or more drove out of the country on Saturday under a heavy escort, amid the worst violence in the capital and in Benghazi since Washington and its NATO allies helped topple Muammar Gaddafi in 2011.
The State Department said embassy staff would return to Tripoli once it was deemed safe.
But analysts said that would be a difficult decision to make given raw memories of the Benghazi attack, which sparked sustained Republican criticism of Obama and his then secretary of state, Hillary Clinton - who is widely expected to run for the White House in 2016.
Republicans charged that the administration did not provide sufficient security for the mission, did not respond quickly enough and then tried to cover up its shortcomings. Harm to another diplomat in Libya would be disastrous for Obama.
Jon Alterman, head of Middle East program at the Center for Strategic and International Studies think tank in Washington, said the United States could not afford to think of the symbolical impact of withdrawing its diplomats when lives were at risk.
"The job of an embassy is to talk to a government. If it's unclear who you can talk to and who can help provide security then that shifts the equation," Alterman said.
"Embassies rely a lot on local governments to both secure them and also to provide intelligence that helps us secure them. And if that isn't working then you have to look quite closely at you security plan and whether you can actually protect the facility."
But he added he did not expect the embassy closure to be long-term, like that in Somalia after anti-U.S. violence in the 1990s, and noted that Tripoli embassy had been evacuated during the fall of Gaddafi and then re-staffed.
Some of the impact of evacuating an embassy is appearance.
"Of course it looks bad - countries normally try to keep their embassies open as long as they can," said Francois Heisbourg, a security expert at the Foundation for Strategic Research think tank in Paris.
"What would be a problem would be if the Americans stayed out for long period. The decision to close may have come quite naturally, but it's going to be a very difficult responsibility to reopen the embassy. That is one where the ghosts of Benghazi are going to come back again."
The State Department sought to play down suggestions that the evacuation would further hamper efforts to stabilize Libya.
"Although embassy personnel are no longer in Libya, we continue to engage the Libyan government on a wide range of issues," department spokeswoman Jen Psaki said on Saturday.
The surging violence in Libya prompted fresh criticism of Obama from Republicans keen to portray the administration as weak on all fronts.
"The administration sort of took its focus off of Libya and things have been getting worse for quite some considerable time now," Ed Royce, chairman of the U.S. House foreign relations committee, told CNN on Saturday after news of the U.S. diplomats' departure.
Robin Wright of Washington's Wilson Center think tank, who was a close friend of Ambassador Stevens, said all NATO countries, not just the United States, had "increasingly abandoned Libya over the past three years."
"Now the central government has crumbled to the point that it doesn't even control Tripoli Airport, much less large swaths of the country," she said. "The long-term danger to the region is that Libya itself crumbles - either into a failed state, or unruly fragments that, in turn, have rippling impact on Africa and the Arab world." (Reporting and writing by David Brunnstrom; Additional reporting by Missy Ryan, Mark Hosenball, Phil Stewart, Emily Stephenson and Arshad Mohammed; Editing by Frances Kerry)