The slogans on the right:
Raise vigilance - Defend the motherland! Strengthen the dictatorship of the proletariat! (提高警惕 保卫祖国! 加强无产阶级专政!)
The caricatures bottom right: a spy with a dagger and a spy with earphones, a transmitter marked "US" and a serpent's tail. He looks a bit like Chiang Kai-shek.