Continued from page 3

Outside of war zones such as Iraq and Afghanistan, U.S. diplomatic facilities generally rely on a mix of locally contracted security guards and the police and security forces of the host country. In post-Gadhafi Libya, a nation awash in small arms and heavy military hardware, that meant hiring local militias to provide security for the consulate.

“No matter what countermeasures you put in place, they can always be outgunned,” said Mr. Kraft, who retired in 2004 and recently wrote the first unclassified guide to the organizational structure of the overall U.S. counterterrorism effort.

With automatic weapons and rocket-propelled grenade launchers, the militants carrying out the Benghazi attack likely would have “exceeded the fire power of a typical diplomatic post defense,” former State Department spokesman P.J. Crowley told The Times in September.

But even a small military force can make a big difference under the right circumstances, said retired Army Col. Thomas F. Lynch III, a special adviser on counterterrorism to Navy Adm. Mike Mullen when he was chairman of the Joint Chiefs of Staff.

Tactical details like lines of fire, setback distance between the buildings and the street, and other objects that provide cover for attackers “are just as important as the numbers” in determining the outcome of any firefight, said Mr. Lynch, whose decade of work in the region included being responsible for the security of military facilities in the Persian Gulf.