Doonesbury by Garry Trudeau for June 09, 1972
Transcript:
B.D.: Dear Phred, Thanks for your letter. It was good to hear from you. I note you say that the Commies are planning to take Hawaii. I don't know if that was supposed to be a joke, but I didn't find it very funny. Friend or no friend, if you or any other Commie dares attack my country, I'll personally shoot your brains out. My best to your mother, B.D.