The recently released video message from al Qaeda’s number two leader is part of a pattern that signals a countdown to a major terrorist attack within the next 30 days, warns a Washington D.C.-based analyst.

The theory, based on a pattern observed after previous terrorist attacks had occured, is that…

…it is not the content of the video that is a sign of a possible imminent strike, said terrorism expert Christopher L. Brown. Instead, it is the timing of the video that is consistent with previous patterns. Brown, a researcher with a Washington think tank, has briefed members of Congress and senior administration officials on key threats, and he has prepared testimony and briefing materials for officials at the Department of Defense, State Department, CIA, National Security Council and the White House.

The pattern Brown observed is that each Zawahiri video appears to be part of a pair, with the second video followed by a significant attack within 30 days, outside of the major combat zones of Iraq and Afghanistan.

The videos released on Sept. 9 and Nov. 9, 2004, were the first “set” and were followed by the Jeddah, Saudi Arabia, bombings on Dec. 6, 2004. The second “set” of videos was released Feb. 20 and June 26, 2005, followed by the July 7 London bombings. A third set of videos was released Aug. 4 and Sept 1, 2005, followed by the bombings in Bali, Indonesia, on Oct. 1, 2005.

It’s all here.