WASHINGTON - The White House has put special operations strike forces on standby and moved drones into the skies above Africa, ready to strike militant targets from Libya to Mali - if investigators can find the al-Qaida-linked group responsible for the death of the U.S. ambassador and three other Americans in Libya.
But officials say the administration, with weeks until the presidential election, is weighing whether the short-term payoff of exacting retribution on al-Qaida is worth the risk that such strikes could elevate the group's profile in the region, alienate governments the U.S. needs to fight it in the future and do little to slow the growing terror threat in North Africa.
Details on the administration's position and on its search for a possible target were provided by three current and one former administration official, as well as an analyst who was approached by the White House for help. All four spoke on condition of anonymity because they were not authorized to discuss the high-level debates publicly.
The dilemma shows the tension of the White House's need to demonstrate it is responding forcefully to al-Qaida, balanced against its long-term plans to develop relationships and trust with local governments and build a permanent U.S. counterterrorist network in the region.
Vice President Joe Biden pledged in his debate last week with Republican vice presidential nominee Paul Ryan to find those responsible for the Sept. 11 attack on the U.S. Consulate in Benghazi that killed Ambassador Chris Stevens and three others.
"We will find and bring to justice the men who did this," Biden said in response to a question about whether intelligence failures led to lax security around Stevens and the consulate. Referring back to the raid that killed Osama bin Laden last year, Biden said American counterterror policy should be, "if you do harm to America, we will track you to the gates of hell if need be."
The White House declined to comment on the debate over how best to respond to the Benghazi attack.
The attack has become an issue in the U.S. election season, with Republicans accusing the Obama administration of being slow to label the assault an act of terrorism early on, and slow to strike back at those responsible.
"They are aiming for a small pop, a flash in the pan, so as to be able to say, `Hey, we're doing something about it,'" said retired Air Force Lt. Col. Rudy Attalah, the former Africa counterterrorism director for the Department of Defense under President George W. Bush.
Attalah noted that in 1998, after the embassy bombing in Nairobi, the Clinton administration fired cruise missiles to take out a pharmaceutical factory in Sudan that may have been producing chemical weapons for al-Qaida.
"It was a way to say, `Look, we did something,'" he said.
A Washington-based analyst with extensive experience in Africa said that administration officials have approached him asking for help in connecting the dots to Mali, whose northern half fell to al-Qaida-linked rebels this spring. They wanted to know if he could suggest potential targets, which he says he was not able to do.
"The civilian side is looking into doing something, and is running into a lot of pushback from the military side," the analyst said. "The resistance that is coming from the military side is because the military has both worked in the region and trained in the region. So they are more realistic."
Islamists in the region are preparing for a reaction from the U.S.
"If America hits us, I promise you that we will multiply the Sept. 11 attack by 10," said Oumar Ould Hamaha, a spokesman for the Islamists in northern Mali, while denying that his group or al-Qaida fighters based in Mali played a role in the Benghazi attack.
Finding the militants who overwhelmed a small security force at the consulate isn't going to be easy.
The key suspects are members of the Libyan militia group Ansar al-Shariah. The group has denied responsibility, but eyewitnesses saw Ansar fighters at the consulate, and U.S. intelligence intercepted phone calls after the attack from Ansar fighters to leaders of al-Qaida in the Islamic Maghreb, or AQIM, bragging about it. The affiliate's leaders are known to be mostly in northern Mali, where they have seized a territory as large as Texas following a coup in the country's capital.
But U.S. investigators have only loosely linked "one or two names" to the attack, and they lack proof that it was planned ahead of time, or that the local fighters had any help from the larger al-Qaida affiliate, officials say.
If that proof is found, the White House must decide whether to ask Libyan security forces to arrest the suspects with an eye to extraditing them to the U.S. for trial, or to simply target the suspects with U.S. covert action.
U.S. officials say covert action is more likely. The FBI couldn't gain access to the consulate until weeks after the attack, so it is unlikely it will be able to build a strong criminal case. The U.S. is also leery of trusting the arrest and questioning of the suspects to the fledgling Libyan security forces and legal system still building after the overthrow of Moammar Gadhafi in 2011.
The burden of proof for U.S. covert action is far lower, but action by the CIA or special operations forces still requires a body of evidence that shows the suspect either took part in the violence or presents a "continuing and persistent, imminent threat" to U.S. targets, current and former officials said.
"If the people who were targeted were themselves directly complicit in this attack or directly affiliated with a group strongly implicated in the attack, then you can make an argument of imminence of threat," said Robert Grenier, former director of the CIA's Counterterrorism Center.
But if the U.S. acts alone to target them in Africa, " it raises all kinds of sovereignty issues ... and makes people very uncomfortable," said Grenier, who has criticized the CIA's heavy use of drones in Pakistan without that government's support.
Even a strike that happens with permission could prove problematic, especially in Libya or Mali where al-Qaida supporters are currently based. Both countries have fragile, interim governments that could lose popular support if they are seen allowing the U.S. unfettered access to hunt al-Qaida.
The Libyan government is so wary of the U.S. investigation expanding into unilateral action that it refused requests to arm the drones now being flown over Libya. Libyan officials have complained publicly that they were unaware of how large the U.S. intelligence presence was in Benghazi until a couple of dozen U.S. officials showed up at the airport after the attack, waiting to be evacuated - roughly twice the number of U.S. staff the Libyans thought were there. A number of those waiting to be evacuated worked for U.S. intelligence, according to two American officials.
In Mali, U.S. officials have urged the government to allow special operations trainers to return, to work with Mali's forces to push al-Qaida out of that country's northern area. AQIM is among the groups that filled the power vacuum after a coup by rebellious Malian forces in March. U.S. special operations forces trainers left Mali just days after the coup. While such trainers have not been invited to return, the U.S. has expanded its intelligence effort on Mali, focusing satellite and spy flights over the contested northern region to track and map the militant groups vying for control of the territory, officials say.
In northern Mali, residents in the three largest cities say they hear the sound of airplanes overhead but can't spot them. That's standard for drones, which are often invisible to the naked eye, flying several thousand feet above ground.
Residents say the plane sounds have increased sharply in recent weeks, following both the attack in Benghazi and the growing calls for a military intervention in Mali.
Chabane Arby, a 23-year-old student from Timbuktu, said the planes make a growling sound overhead. "When they hear them, the Islamists come out and start shooting into the sky," he said.
Aboubacrine Aidarra, another resident of Timbuktu, said the planes circle overhead both day and night. "I have a friend who said he recently saw six at one time, circling overhead. ... They are planes that fly at high altitudes. But they make a big sound. "
Callimachi reported from Bamako, Mali.