Anti-American Art: Buddies

My limited knowledge of Chinese tells me that this Cultural Revolution era poster is exalting the friendship of the peoples of three nations against their common enemy. I'm not sure who the third friend to the Chinese & Vietnamese people is. I'm guessing Laos? Anyway who these inseparable buddies are not letting into their club is revealed in the lower right of the image: that's an American GI's helmet and the indistinct but identifiable wreckage of an American airplane in flames. These guys sure do look like they're fans at a sporting event instead of participants in a battle, but what the heck. Fortunately they don't let people take AK47's into the stands of ball games.