From the Political Insider blog at the AJC:
A University of Georgia researcher has determined that the world’s most powerful nations — including the United States — have had only a 39 percent success rate in military actions since World War II.
And based on her calculations, the current war in Iraq has a 26 percent probability of success — with an estimated duration of 10 years.
Apparently the study indicates that the cooperation of the adversary is a key factor affecting the odds of success of the military action.
It would seem to me that this should shed a bit of light on the administration’s stance of refusing to talk with entities that have some influence over Iraqi insurgents, like Iraq and Syria.