Absolutely lost his compass if he ever had one.  Running the war from Washington during the Vietnam campaign (war) didn't work out so well for the US.  Put a microphone in front of McCain and it fire ready aim.  Let Mattis and his staff, generals on the front develop a plan.  What these generals need to know from congress what the overall budget for the military entails.

McCain would do well to focus on the budget- defense budget.  Not sure he has accepted, the American voter had a chance to support him on national and global thought processes, and by my standards the answer was clearly a no.  Give the defense department, strong congressional support, via clean budget and removing sequestration.  If he has any weight to throw around this should be the area he focuses on.