Admiral McRaven and other officials noted that the Pentagon’s evolving national security strategy calls for building counterterrorism capacity among local forces in allied and partner nations, rather than having American troops on the ground carrying out those missions.

He also acknowledged that there would be some risk in training security forces in a country where militias have shifting ties and some who enter the training program might have questionable backgrounds.

In particular, he cautioned that it would be very difficult to vet fully all Libyan personnel who might be trained by Americans to guarantee they had unblemished backgrounds.

“There is probably some risk that some of the people we will be training with do not have the most clean record,” Admiral McRaven said. “At the end of the day, it is the best solution we can find to train them to deal with their own problems.”