THE TAKING of American hostages by Islamic militants who attacked a gas field in Algeria on Wednesday served to underline the reality that al-Qaeda in the Islamic Maghreb (AQIM) and the jihadist factions affiliated with it pose a direct threat to the United States. The group is active not just in Algeria and neighboring Libya — where it is believed to have played a role in the fatal attack on the U.S. Consulate in Benghazi in September — but also in Mali, where militants have taken over territory the size of Texas and threatened to capture the rest of the country.

As Defense Secretary Leon Panetta succinctly put it Wednesday, “This is an al-Qaeda operation, and it is for that reason that we have always been concerned about their presence in Mali, because they would use it as a base of operations to do exactly what happened in Algeria.”

Under those circumstances, the Obama administration’s foot-dragging in providing support to an ongoing French intervention in Mali is baffling — and disturbing. This week the White House grudgingly agreed to help transport a French mechanized unit and its equipment from France to Mali. But Paris will be required to pay the $20 million cost of the operation, and officials are still sitting on a week-old French request for U.S. help with surveillance and aerial refueling.

The administration’s balking might be more understandable if there had been no previous U.S. involvement in the north African state. But the United States already has spent years and millions of dollars attempting to stem Islamic extremism in Mali — and its failures helped to precipitate the current crisis. Last year counterterrorism forces trained by the United States defected to a rebel movement of ethnic Tuaregs, which then allied itself with al-Qaeda and its local allies. The rebellion was boosted by Tuareg fighters who streamed into Mali after the regime of Moammar Gaddafi, which employed them, was deposed thanks to an intervention by NATO. Meanwhile a U.S.-trained officer led a coup against Mali’s democratic government.

The Obama administration has already voted for a military intervention in Mali, supporting a U.N. Security Council resolution that authorized action by a force from West African countries. Washington insisted on an unrealistic scheme to postpone the intervention until late this year — even as 400,000 people fled the Islamic reign of terror in northern Mali — arguing that it should be preceded by democratic elections. That plan exploded when the Islamists launched an offensive to capture the capital, Bamako; France was right to quickly dispatch planes and troops to prevent a catastrophe.

So why won’t the administration meet its NATO ally’s request for aid? Officials claim there are legal problems: Because of the coup, military aid to Mali is prohibited by U.S. law. But AQIM’s taking of American hostages makes the group a legal target for U.S. forces under the doctrine of self-defense. There are worries that the French may find themselves fighting not al-Qaeda but the Tuaregs. But the ethnic rebels have allied themselves with the jihadists, who have pushed the war beyond the Tuaregs’ homeland.

Thanks to France, U.S. troops are not needed in Mali. But it is time for the administration to recognize that AQIM poses a direct threat to Americans — and to fully support the military action needed to eliminate it.