Maybe my memory is off base but my sense is McCain supported the "more boots on the ground" side of what's going on in Iraq.
If so, this would help explain why he is so anti-Rumsfeld as well as past complaints against President Bush and what we are doing in Iraq. It also means if there were a President McCain, he would turn the military back to what it was before all the modernization we went through, which has turned out well and created an even better US military.
My point is, saying McCain is good on Iraq is not necessarily the best credential for his running for president. Add in all his other blunders and it is hard to envision him winning any national election.
I can't forgive him for wanting Geneva Convention treatment for these terrorists at Gitmo.