"I believe all of them." Do you mean you believe what they say? Which would mean that when some former soldier says Kerry is a liar, you believe him? And that a bthe same time, if Kerry says that's a lie, you believe him too?

Or do you mean that, regardless of what they say, you believe that they believe they are telling the truth?

Or is it that it's no business of anybody to question the truth of anything someone who has been in uniform says? But when they start accusing each other of lying? In paid advertisements?