WASHINGTON -- The ''shock and awe" attack that toppled Saddam Hussein in three weeks is often touted as a brilliant strategy that defeated Iraq with relatively few US casualties. But new information suggests that the United States may have played into Hussein's plans for a quick war followed by a long guerrilla insurgency....

Indeed, intelligence officials said that instead of reading up on tank warfare, Hussein and some of his top generals are believed to have been boning up on books penned by Vietnamese communists on guerrilla warfare tactics....

The United States should not have been surprised, according to officials and outside analysts. Signs that a guerrilla war might be in the offing were apparent before the United States invaded. Nonetheless, the Defense Intelligence Agency and the intelligence branches of the Army, Navy, and Air Force do not appear to have given them much credibility or passed concerns up the chain of command, they said.