Chinks in Our Armor

Listen up, buttercup. This joke plays on the word "chink," which is a really nasty slur for Chinese people. The punchline uses it in place of "kinks" to make a pun about finding a weakness in the US Army's "armor." It's supposed to be funny because of the unexpected and offensive twist, but it's mostly just offensive. You wouldn't get it, because you probably think that is funny. No amount of explanation will make it more funny because it just ain't.