Answer: Brezhnev dashes Czech hopes.
Explanation: Indeed, this cartoon refers to the Prague Spring, the period of democratic reforms and liberalization that took place in the Socialist Republic of Czechoslovakia between January and August of 1968. Citizens were given more freedom of expression and travel. The Media were given less restrictions to criticize or mock the authorities. Governmental administrative authority was decentralized.
The Soviet Union and conservative elements of Czechoslovakia government were displeased with these measures and Leonid Brezhnev, leader of the Soviet Union ordered an invasion of Soviet troops in late August. 650,000 soldiers and 2,000 tanks invaded the little country and deposed the government, replacing it with hard-line loyalists. The character in the cartoon is Brezhnev, the candle he is dashing is the Czech spirit that fought for freedom. The metal military helmet he is using represents the military invasion that dashed these hopes.