WWIII in 2012?

A report Panetta has either heard of or was told directly was reported in the Washington Post by David Ignatius saying there is a strong likelihood Israel will attack Iran in April, May, or June. Needless to say Panetta refused to comment on the subject. he said, "What I think and what I view, I consider to be an area that belongs to me and nobody else."

Could this be true? What implications would this have? Would the U.S. get involved?