No special relationship

There are no strong historical ties—no “special relationship”—between Russia and China, as there is between, say, the United States and Great Britain.

The Soviet-Chinese alliance of the 1950s, based on shared ideology, came to an end when ideologies shifted. The two countries quickly became adversaries and, in the late 1960s, even fought a short, sharp border skirmish.

The most likely explanation for today’s closer ties is that it’s simply better to be friends than enemies. The Sino-Russian border is 2,670 miles long. The manpower and resources it would take to defend it would be crippling to both sides.

Bad relations between the two countries could easily tie up the entire Russian army, or force China to boost its military spending even higher.

It’s much easier for Moscow and Beijing to try to get along—or pretend to, anyway. The Americans are less dangerous to either Russia or China than the latter are to each other.

China and Russia would both prefer to keep the United States out of Asia and the Pacific. China wants a free hand in Asia and the South and East China Seas and believes it is now powerful enough to carve out its own sphere of influence.

It does not, however, believe it is powerful enough to pull that off on its own.

For its part, Russia wants to keep the Americans out because it’s weak in the Asia-Pacific. As it stands, Russia can barely defend its historical territories, let alone project a security buffer into the Pacific Ocean. Aligning with China creates enough uncertainty and ambiguity to give an opponent pause.

There are other benefits. China buys Russian military equipment it can’t build on its own, particularly new fighters and submarines. This affords China time to research key technologies—metallurgy, for one—while continuing to modernize the People’s Liberation Army.

Russia gets hard currency—$13.2 billion from arms sales in 2013, with China the second largest client.