This week, the Chinese and Russian militaries began the first joint naval exercises the two sides have ever conducted.

The exercise, occurring near Qingdao on the Yellow Sea, will involve 16 Chinese surface combatants and two submarines, including five missile destroyers, five missile frigates, and four missile boats, as well as a resupply ship and one of China’s new hospital ships. These are most likely drawn from the Chinese Northern Fleet, which is headquartered in Qingdao.

The Russian contingent is comprised of four surface combatants, including the Slava-class cruiser Varyag and three Udaloy-class anti-submarine destroyers, as well as several supply vessels. The exercises, according to news reports, will include joint air defense, anti-submarine warfare, and search-and-rescue operations, as well as the now de rigueur “anti-terrorist” drills.

While China and Russia have engaged in various military exercises since the first “Peace Mission” exercise in 2005, those have been conducted within the framework of the Shanghai Cooperation Organization (SCO). In most instances, there have been at least nominal contingents from other SCO members. This year, however, the exercises are being staged as purely bilateral operations between Russia and China.

This potentially marks a significant advance in Sino-Russian military cooperation. Taken in conjunction with Sino–Russian diplomatic cooperation on such issues as Syrian sanctions, it may reflect a further deepening of a Moscow–Beijing axis.

Alternatively, however, it may reflect an attempt by both sides to focus attention on one of the few areas of cooperation and away from deeper, systemic problems between the two states. The growth of the Chinese economy, Russian demographics, and a steady return of residents to European Russia from the Russian Far Eastern and Siberian districts has resulted in the economic center of gravity in Asian Russia shifting southwards to China.

Moreover, Russian arms sales to China have dropped in the past decade, both because China’s military industry has become more sophisticated and because Chinese lack of respect for intellectual property rights extends to Russian military equipment.

When coupled with Chinese military modernization, the regional balance of power on the Asian mainland seems to be moving steadily against Moscow. This is sufficiently alarming that some Russian analysts, such as Sergei Rogov of the Russian Academy of Sciences, have openly discussed the growing role of nuclear weapons in safeguarding Russia’s security interests, including in Asia.

It remains to be seen how the incoming Chinese leadership will deal with its neighbors. When Xi Jinping and Li Keqiang take over in the fall, it may presage a Chinese “reset” of its foreign policies—and whether this is the first or last such joint exercise.