Adam Goldman

The United States is not immune from terrorist attacks, as December's Islamic State-inspired mass shooting in San Bernardino, California, demonstrated. And its transit systems are vulnerable. But the U.S. is not grappling with the same volume of Islamic State recruits as its European peers.

Although the Russians are relying on a show of force at the Games, deploying 40,000 heavily armed police and other security officials to the area, the security risks are regarded as unusually high compared with past Olympics. The main threat emanates from Islamic radicals who are based in the nearby Caucasus and who have vowed to launch attacks during the event.

WASHINGTON -- A long-delayed Senate Intelligence Committee report released Wednesday faulted both the State Department and the intelligence community for not preventing attacks on two outposts in Benghazi, Libya, that killed four Americans, including a U.S. ambassador, about 16 months ago.

An American who vanished nearly seven years ago in Iran was working for the CIA on an unapproved intelligence-gathering mission that, when it came to light inside the government, produced one of the most serious scandals in the recent history of the CIA — but all in secret, an Associated Press investigation found.