Earlier today, China and Russia began a six-day joint naval exercise in the Yellow Sea. "The exercises will involve several simulated missions, including the rescue of a hijacked ship, the escort of a commercial vessel and the defense (of) a convoy from air and sea attacks," a Russian defense ministry spokesman said Friday, according to Russia's RIA Novosti news agency. According to the Xinhua news agency, the exercises will involve over 4,000 Chinese servicemen, "16 Chinese vessels and two submarines, as well as 13 aircraft and five shipboard helicopters, four Russian warships and three Russian supply ships."
These exercises come at a time of generally heightened tensions in the Asia-Pacific, more recently in the Korean peninsula with the failed missile launch from North Korea. Broadly speaking the waters around Japan, Korea, and China and south toward the South China Sea and Philippine Sea have been hot-spots for international incidents over the last few years. Japan took a Chinese fishing captain prisoner, only returning him when the Chinese banned exports of rare earth elements to Japan, and China has contested waters and islands between the Philippines and others, often in the search for energy.
China and Russia both tend to irritate the U.S. when it comes to national security issues. Russia has been a staunch supporter of Syria recently and relies on them for weapons purchases. China is also a major purchaser of Russian arms, though they are becoming less reliant. Both China and Russia are seeking to build up their blue water capabilities. China is working on converting a Russian cruise ship into an aircraft carrier, and Russia has laid out plans to build an operational aircraft carrier by 2020, though this goal is seen by many as out of reach. This exercise can be seen as a reminder to the rest of the world, and specifically the Asia-Pacific countries, that China and Russia are still allies, still have significant interests in the region, and still should be respected from a naval perspective. While the exercises have an anti-pirate feel to them, they can also be considered preparation for any such event that pits the U.S. and its allies in the region against the two most powerful autocratic government in the world.