Ultimate Weapon by Chris Ryan
This book features three people, three stories, and a desperate race for survival in a country in the midst of war. Nick Scott fought in the SAS during the first Gulf War. Captured and tortured, he was left a broken man. His daughter, Sarah Scott is a beautiful young scientist who has cracked one of the scientific secrets of the age. Now, she has vanished. Her lover, Jed Bradley is one of the SAS's toughest young agents, dropped behind enemy lines in the build up to the Iraq War to find the truth about Saddam Hussein's weapons of mass destruction. Caught up in a global power play, Nick and Jed must fight their way through a war-ravaged Iraq as the regime of Saddam Hussein collapses around them. It is a desperate race to find the woman they both love, and to unlock the secret of the Ultimate Weapon.