A rabbi is sitting on an airplane next to a Korean guy. After they have been flying together in silence for a while, the rabbi leans over and says, "You know, I've never forgiven you Chinese for what you did at Pearl Harbor."
The Korean looks shocked and replies, "What the hell are you talking about?!?!? It was the Japanese the bombed Pearl Harbor, not the Chinese. And besides, I'm not Chinese or Japanese, I'm Korean!"
The rabbi says, " Korean, Japanese, Chinese, what's the difference?"
A little while later, the Korean man says, "You know, I've never forgiven you Jews for sinking the Titanic."
The rabbi looks confused and mad and says, "What are you talking about? The Jews didn't have anything to do with that! An iceberg sank the Titanic!"
The Korean guy replies, "Iceberg, Goldberg, Greenberg, what's the difference?"