Without realizing it, al Qaeda is calling on its troops to make a homage to Japanese World War II infantry tactics, by making a Banzai Charge. Al Qaeda has called on all True Believers to make whatever kind of attack they can, especially in the West. This was very similar to a spectacular tactic Japanese troops used when they knew they were beaten.
The image most people have of the Japanese army during World War II is a mass of fanatical guys launching a hopeless charge led by officers waving katana (samurai swords). This was the Banzai charge and these attacks did occur, and made a vivid impression on the defending troops. But most of these attacks failed.
Al Qaeda is in a much worse situation than the World War II Japanese. First of all, few al Qaeda members are as competent and diligent as the average Japanese soldier. Most al Qaeda recruits are illiterate, and, while often fanatic, not well disciplined. The few competent planners and technicians they had have been considerably depleted by a decade of attacks by Western troops and intelligence agencies. But Islamic radicals gained some media traction with their claims to be defending Islam from infidel (non-Moslem) attack. This inspires many young Moslems, especially the illiterate and poor, or those literate and fortunate Moslems living in the West who feel they are not getting sufficient respect from their infidel neighbors. To these Moslems, especially, al Qaeda is calling for a Banzai Charge. There have already been some of these attacks. Some involve guns or knives, others use a car driven into a crowd of unbelievers. Bombs have not been as successful, despite all the technical advice available on the web from al Qaeda bomb makers. But there are plenty of Moslems living in Western nations who openly admit their admiration for suicide attacks. If you can’t win, you can at least go out in a mayhem of senseless slaughter.