The war in Iraq will always be remembered for the failures of intelligence that preceded it and the insurgency that bedeviled coalition forces long after President George W. Bush declared an end to major combat operations. Amid all that disaster, the capture of Saddam Hussein has become a forgotten success story. It's an accomplishment that wasn't inevitable. In a five-part series that begins today, I'll explain how a handful of innovative American soldiers used the same theories that underpin Facebook to hunt down Saddam Hussein. I'll also look at how this hunt was a departure in strategy for the military, why its techniques aren't deployed more often, and why social-networking theory hasn't helped us nab Osama Bin Laden.