If you want to write a novel that will be outdated really fast then write a science fiction novel about momentous world events that take place immediately after your publication date. This book was outdated even before it was published though. It was published in December of 2001 and I suppose it was too late to figure in the events of September 11, 2001, but if it had not, those events would have been a prominent part of this story. If you read this as an alternate history, though, it works quite well and is a very entertaining story.
It seems that a security guard in an Amsterdam museum in 2004 picks up an old sword and before he knows what's happening he is fighting in the First Crusade about 900 years in the past. He doesn't actually travel through time, but rather, he is reliving a past incarnation. No, this is science fiction, not a fantasy. It is later in the book that reincarnation is placed in a scientific sounding context. When he gets back to the twenty-first century he finds himself in the position of being a major player in World War III in the first decade of the century. That war culminates in all hell breaking out in May of 2008. Throw in an entity from outer space called the Galactic Mind that tries to direct certain characters to end the war so that it can absorb humanity into itself and this story really does work out to be very entertaining. Be prepared for a major turn-around and surprise perpetrated by the Galactic Mind in the last few pages.