A long-awaited Senate report on the 2012 attacks in Benghazi, Libya, sharply criticized American diplomats and spies, saying the assault that killed four Americans was "likely preventable" with better security and intelligence operations.

The bipartisan report released Wednesday by the Senate intelligence committee represents the most comprehensive analysis to date of the U.S. government's actions in the lead-up to the attacks on the diplomatic compound, and their aftermath. It reinforced conclusions of previous reviews...