In 1949, shortly after the communists took power in Beijing, a photographer captured Joseph Stalin and Mao Zedong in Moscow, faces turned away from each other with serious expressions.
It's hardly a picture of fraternal feeling.
But the path to that moment was a surprisingly torrid one, paved by liaisons and sex decades earlier in Russia, which had become a place of study and romance for Chinese revolutionaries – and, even before then, an object of yearning for young Chinese people smitten by the country's novelists.
It wasn't Marx and Lenin alone who brought communism to China.
It was also the siren song of Anna Karenina, drawing Chinese interest to Soviet Russia, where human and ideological passions then intermingled.
Some of the Chinese who fell in love in Russia eventually came to play prominent roles in bringing communism to China.
That's the little-known story historian Elizabeth McGuire tells in her new book, Red at Heart: How Chinese Communists Fell in Love with the Russian Revolution.
Why did Chinese revolutionaries fall in love with Soviet Russia, and not France, where some of them first went to study?
These young students are going to France and they're in Catholic schools and what they're seeing around them is not a super revolutionary society. They're not finding the radical solutions that they're looking for.
And it's a combination of being disillusioned with the idea of democracy, and them also being disillusioned with their actual experience that causes that turn away.
As far as Russia is concerned, in the late 19th century, the Chinese were really interested in Russian anarchism. Then they go totally nuts over Anna Karenina and 19th-century Russian literature – which is super romantic, right? This is at a time when these young rabble-rousing Chinese guys are trying to get rid of Confucianism. They don't want their arranged marriages. They want to fall in love.
The Chinese really only understood Marxism way later. They were excited first by this Russian culture. It was almost like an alternate vision of personal, national, cultural liberation that was on display in revolutionary Russia, and in such an exciting way, such a sexy way.
It was this 1920s fizzy cocktail whose hangover just lasted.
Sex is an intriguingly central part of the story when Chinese students began to flock to Russia. Were you surprised to find communism so steamy?
It was really surprising just how much time and energy they all seemed to spend be spending on their love and sex lives. But what I realized is that sex is a metaphor – it stands for this really serious human interest and process of communication. It stands for mutual attraction. And the sex shows that these two cultures suddenly became fascinated with each other. Something really exciting politically was going on with something really exciting personally.
So how does looking at Sino-Soviet romance change the way we understand how communism spread?
It wasn't romance like love and happiness. It was romance in the sense of a stormy, emotional, tragic, fickle, human relationship. It was the product of a lot of individual human relationships, and then that created a larger experience, a generational experience for Chinese communists. It was a real moment of cultural conflation that made what happened with China and Russia possible.
But it created problems in Russia, too, right?
One of the first things the Bolsheviks did is they legalized divorce and abortion, which is obviously a very emancipatory thing to do for women. So there's all this crazy sex [among Chinese students], plus abortion is legal.
And there are not as many Chinese women as men in Russia. So the Chinese men are fighting over the women who are there, and the women are having a lot of sex, and not necessarily with their spouses. Fights break out among Chinese men, and there was a rape and physical violence – someone pulling a knife on someone.
So the Russians try to calm them down. They finally call in Nadezhda Krupskaya, Lenin's widow, just to talk to the girls and say, "It's okay to have romance and love in your life. But just don't abort the babies, for heaven's sakes, and don't get yourself so worked up about this."
Did the sex continue back in China? Was the The Long March, too, a sex-riven affair?
No. The women on the march were a teeny, tiny minority. You had to be pretty important to take your wife. The march is when the puritanical streak started, because that's when the Chinese revolution turned inward and all of that romanticism faded in the bitter difficulty.
Except guess what: they get to Yan'an and all of a sudden, these Shanghai actresses and young people start making their way there. And all of the sexy stuff starts all over again.
China is now positioning itself as the new cradle of socialism and offering its system as a model for others. Are there lessons from what happened in Soviet Russia? What would it take for Xi Jinping to make "socialism with Chinese characteristic for a new era" sexy?
There's a thing people forget. You can't just plunk down some ideas or a bunch of money.
[With China's new vision of socialism], there's no preceding cultural pull factor. It's not like, say, Pakistan is fascinated by Chinese literature.
How would you make more of a pull factor? I think you have to find points of cross-cultural connection that are real. China is big into soft power right now.
What does it take? You have to be likeable.
But China has a huge advantage over the Soviet Union's ability to "spread the Bolshevik vision." Their problem was that they did not have big communities of Russian people all over the world. China has a huge diaspora.
They may not have some of the natural sexiness of Anna Karenina, but they sure do have the manpower.
This interview has been edited and condensed.