What's the intention of "(What's So Funny 'Bout) Peace, Love And Understanding"?

Is that the bass drum fill? I love that part if so.

My band have been playing this for a long time and in the past few months we start it by playing half a chorus of War - saying we’re going to ask you 2 questions - 'War! - what is it good for? - absolutely nothing!" then straight into “What’s So Funny 'bout P L and U”
I sing it and do so with as much sincerity as I can muster.
There have been occasions recently where I have cried whilst singing it.

MiM