This is one of Vonnegut's early novels, and I really enjoyed it. The story is a fascinating one: an American living in Germany is recruited by the United States to work for the Nazis during WWII and unknowningly assists the Allies with his pro-Nazi radio broadcasts. After the war he is abandoned by the United States out of embarrassment, and is captured by the newly formed nation of Israel and put on trial for his "war crimes." It's an incredible story about identity and being responsible for one's actions. I would confidently say this is one of Vonnegut's best.