* U.S. ready to assist, but not taking the lead
* African forces to get most American help
* Algeria hostage drama highlights regional threats
By Andrew Quinn
WASHINGTON, Jan 17 (Reuters) - The United States is responding cautiously to Mali's widening civil war, hoping to limit U.S. exposure even as French troops go on the offensive against Islamist rebels in the African country and U.S. citizens are caught up in a hostage crisis unfolding in neighboring Algeria.
The escalation of fighting in northern Mali, where West African troops are joining French soldiers battling al Qaeda-inspired rebels, has emerged as the first foreign policy flashpoint facing U.S. President Barack Obama as he begins his second term next week.
True to form, the Obama administration's approach has been measured and wary, promising U.S. logistical assistance but ruling out direct U.S. military involvement in an unpredictable conflict.
"What we are seeing in Mali, in Algeria, reflects the broader strategic challenge, first and foremost for the countries in North Africa and for the United States and the broader international community," Secretary of State Hillary Clinton said on Thursday.
"Instability in Mali has created the opportunity for a staging base and safe haven for terrorists."
Despite those concerns, however, analysts say the cautious U.S. approach demonstrates that Washington sees few immediate security implications for the United States itself and big risks in a French-led military action without accompanying political progress on the ground.
A U.S. official on Thursday said the United States has agreed to a French request for airlift capacity to help France move its troops and equipment to Mali - a relatively modest expansion of U.S. assistance.
"I think the administration is going to be very wary of getting involved in any direct military operations. That will be an absolute last resort," said Jennifer Cooke, director of the Africa program at the Center for Strategic and International Studies in Washington.
"It doesn't want the political aspect of this -- which is vital -- to get lost."
The United States has said it stands behind France's decision last week to launch air strikes and send ground troops to its former colony, where Islamist rebels were pressing southwards after seizing the north of the country following a military coup in March.
But the French move leap-frogged U.S.-backed proposals to concentrate on returning a legitimate government to the capital Bamako, which Washington had long insisted was an essential first step toward restoring order to the country.
"You'd have to ask the French what their exit plan is," said one senior State Department official.
France argued that intervention was essential to prevent a worsening of Mali's conflict, which has displaced an estimated 30,000 people as fighters from groups including al Qaeda's North Africa branch, Al Qaeda in the Islamic Maghreb, and the local Tuareg Islamist group Ansar Dine seized Timbuktu and other towns. They imposed a harsh version of Islamic law, including public amputations and beheadings.
But the United States, already accelerating plans to pull troops out of Afghanistan and fending off pressure for more robust action on Syria, shows little appetite for stepping into a more direct role in Mali.
Defense Secretary Leon Panetta and other U.S. officials say the United States already has boosted intelligence sharing with France.
Other potential areas of U.S. support could include refueling and surveillance including drones, although these are already in high demand in Afghanistan as well as other parts of Africa.
"If we move one to Mali, for example, we take it from somewhere else, where it is also needed," a U.S. defense official told Reuters, speaking on condition of anonymity.
But with U.S. law barring direct support to governments produced by coups such as the fragile interim administration in Bamako, the United States is concentrating on the ECOWAS group of West African nations which on Thursday sent its first deployment of troops into the conflict..
"We do best if we are in a strong supporting and sustaining role, and not in a role in which we are taking the lead," the senior State Department official told reporters on Wednesday. "This is primarily an African problem."
The United States has offered training and non-lethal supplies, ranging from boots and medical kits to maps, to the African forces. It also stands ready to help transport them into Mali, although U.S. officials say this could be done through paying for third countries to airlift the troops rather than using U.S. military personnel or equipment.
Western fears that the al Qaeda-linked insurgents are expanding operations across Northern Africa were underscored on Wednesday when Islamist militants attacked a gas field in neighboring Algeria, taking dozens of foreigners hostage, including some Americans..
While the attack illustrated that U.S. interests remain exposed across an unstable region, few analysts expect it to force a change in Washington's overall approach.
Republican U.S. Representative Mike Rogers, chairman of the House Intelligence Committee, said the parallel crises in Mali and Algeria, like the deadly Sept. 11 attack on the U.S. mission in Benghazi, Libya, showed the need for a broad and sustained push to bolster unraveling security in the region.
"You can't just handle Mali. You can't just handle the Tuareg. You can't just handle Benghazi. You have to have an overarching plan that puts pressure on these groups from all of it," Rogers told CNN on Wednesday.
"And you can't just fire a few missiles and pack up and go home and hope for the best. It's not going to work."
Some analysts expect the United States will continue to try to buy time, giving notional support to France while at the same time pressing for a more durable political solution for Mali.
"Fundamentally we have to face the reality that what we have here is an insurgency, and we have to fight a counterinsurgency," said J. Peter Pham, director of the Michael S. Ansari Africa Center at the Atlantic Council.
"You cannot fight a counterinsurgency unless you have a legitimate government to rally around, and that is what we do not have in Mali right now."