During a video conference last week, Russian President Vladimir Putin said something significant. When asked if Russia would enter into a formal military alliance with China, Putin responded: “We don’t need it, but, theoretically, it’s quite possible to imagine it.”

That may not seem like a big deal, until you realize that the Russians have consistently avoided using the word “alliance” to describe their relationship with the Chinese. Instead, they’ve described their increasingly close ties as a “comprehensive strategic partnership of coordination.” It may be the case that “alliance” implies certain military commitments that go beyond how the Kremlin and Beijing currently view their dealings. Or, they may want to leave some ambiguity, avoiding terms that crystallize the situation for policymakers around the globe.

Either way, there is little doubt that their “strategic partnership” has already led to an alliance, of sorts, between the Russian and Chinese militaries. Putin conceded as much during the conference call. “Without any doubt, our cooperation with China is bolstering the defense capability of China’s army,” Putin said, according to the Associated Press’s account of his remarks.

Indeed, as I noted in a previous edition of Vital Interests, the U.S. Department of Defense has found that the Sino-Russian partnership “entails a relatively high degree of military cooperation,” which “occurs in practical forms through exchanges of training, equipment, technology, high-level visits, and other coordination mechanisms.” The two countries have engaged in a number of joint exercises, with Russia supplying China various forms of weaponry and aircraft. Late last year, the Kremlin pledged “to assist China in developing their missile-attack early warning network,” while the two sides have agreed to cooperate as far afield as the Arctic.