From his wikipedia article....
He did join the army so he could go to Vietnam, but never ended up going. Yes, of course he is lying, and of course he did
really not want to go to Vietnam and angled his way out it. But, since he served in the National Guard, I think it would be unfair to fully classify him as a chickenhawk.
Keep in mind, Ron Paul is in many respects, his opposite. Paul went to war (not in heavy combat), but then again, Paul opposed the war, and did not support it. So, despite my strong disagreements with Bolton on foreign policy, I cannot consider him a chickenhawk in the form of Dick Cheney or Newt Gingrich.