From what I've read the fumble was the result of a difference of opinion and poor communication between the U.S. State Department (more aggressive) and the Pentagon (more risk averse). Poland just got caught in the middle.

EDIT: The second instance of being flat-footed I was referring to was entering intense diplomatic dialogue with China in an attempt to get them to avoid making any concrete commitments, and then discovering (based on direct and indirect feedback during talks) that China is already much further down that road than we assumed.