At the beginning of 2003, weapons of mass destruction were at the top of NATO’s agenda. Divisions among the allies over how to deal with Iraq, and what roles NATO should play, were unusually open and bitter. Sympathetic commentators worried that the very future of the alliance was at risk. Others let frustration get the better of them and declared that NATO’s time was over. Two years later, the alliance was still standing and the future seemed to be brightening somewhat. But many questions remained regarding NATO’s ability to address WMD proliferation threats, and more generally the new security challenges of the post-Cold War era.