I read a paperback novel at a library about 10 - 15 years ago and want to find it again. However, I can not remember the name or author of the novel, and can not find it in the library. It was about a soldier from the near future who time traveled into the past. In the time he was from there was a war on (or terrorism?) in which the enemy were Arab fighters who belonged to a group with a name something like Unite. I would appreciate it if any one could help me identify the name and/or author of the novel. Thanks!
Extra details, as requested: The time period the soldier traveled into was the present day of when the novel was published, likely sometime in the 1990's. Right now I can not remember other details.