Back when he was Secretary of Defense, there was a large investigative article done about his connections in Indonesia and China, with suspicion that this is why he got the position after Aspin.
I imagine he knows full well what accomodations were made with North Korea and Iraq during the 90's, and would prefer that can of worms not be opened.
He says Iraq is an "elective operation"...doesn't think this is a needed war. Says they don't have a grip on NK...says we are not funding Homeland Security enough..IOW, we are not protecting America as we should.