The immediate winner here is Putin.
On the brink of a war in Ukraine that he knows will cost Russia dearly if it goes ahead, the Russian president is in dire need of allies.
Chinese economic and diplomatic support might just be enough to soften the blow of sanctions and isolation if he chooses to go ahead with an invasion.
Even if he does not give the order for war, a tighter alignment with Beijing will help him project Russian power in what is shaping up to be a long and frosty Cold War Two.
The document doesn't mention Ukraine explicitly. Xi is not, to the best of our knowledge, handing Putin a blank cheque for war.
But by throwing China's full weight behind the grand bargain Putin has demanded from the West, he is giving Moscow much more leverage.
The hope that Xi might be persuaded to restrain his ally or remain aloof – or conversely that Putin could be enlisted to help contain China – has been dashed.
Xi gains a secure northern border and the knowledge he can rely on Russian backing for his own brewing confrontation with the United States and its allies in the Pacific.
The new Eurasian axis will also make it impossible for the United States to pursue its strategy of reducing its European commitments in order to concentrate on the Pacific.
That aspect of the deal is slightly less helpful to Putin, of course. But this is not an alliance of equals.
Russia remains a superpower with global reach, a huge nuclear arsenal and an army that is battle-hardened and effective.
But China is by far the richer, more populous and more powerful of the two. Russian policymakers may be wondering what price Beijing will extract for its friendship further down the line.
For now though, they have a common goal: the end of Pax Americana.