"Greetings, comrade." says the spy, but before he could finish his sentence, the Russian says, "I think you are American spy."
The spy is alarmed, but being a skilled, trained, spy, he says, "That is not true! I am the proudest Soviet there is! I can sing the anthem more beautifully than any other man in the country!"
He then proceeds to sing the Soviet anthem, so melodically and beautifully, that everybody in the bar cheers.
"Very good, very good!" says the politician. "But I still think you are spy."
The man continues to keep his cool.
"I am a historian! I can tell you everything about this glorious country!"
He then spends about two hours recounting the Revolution, the Great Patriotic War, about how superior to the Russia is in terms of technology compared to America and makes a great argument about how communism is beneficial to society.
"Amazing! You are skilled!" says the politician.
The spy smirks.
"But I still think you American spy."
The spy is getting frustrated, but still unfazed.
He replies, "I am good drinker, a true Russian! Let us drink, and see who can come out top!"
The bar turns its attention to the politician and the spy, who are now in a drinking contest.
The bartender serves drink after drink of vodka.
After about an hour of drinking, the politician nearly passes out, unable to hold as much liquor as the spy, to a resounding cheer amongst the bar.
In the midst of the cheering, the Russian politician gets up, smiling, and in a slurred speech, repeats, "You are good, you are good... but I still think you are spy."
The American spy, piss drunk, loses his skill and gives up.
"Okay, you got me. I am an American. But what made you think that way, after all this time?"
The Russian politician replies, "There aren't many black people in Russia."