Intelligence regarding al Qaeda plans to attack U.S. embassies, officials, and interests last Sunday was known for months by U.S. intelligence agencies but was used only recently to trigger the closure of embassies and issuance of public warnings of impending attacks. Al Qaeda “chatter” about coming terrorist operations, mainly against 22 U.S. embassies and consulates, and threats to attack or bomb officials in the Middle East and elsewhere was widely reported in classified intelligence reports over several months. The report said an attack was planned for Sunday, although no attack was carried out. The intelligence was based on electronic surveillance...