On July 23, Russian and Chinese military aircraft made a series of incursions into the airspace around Takeshima (known as Dokdo in South Korea) in Japan's Shimane Prefecture. Seeing this as a violation of its territorial airspace, the South Korean military fired 360 warning shots at the Russian aircraft and demanded that the Russian government prevent any recurrence. Japan lodged protests both with Russia for having violated its territorial airspace and with South Korea for having fired warning shots within Japan's territorial airspace. According to South Korea's Ministry of National Defense, a Russian Air Force A-50 airborne early warning and control (AEW&C) aircraft "violated" the airspace over Takeshima on two occasions shortly after 9am on July 23. South Korean Air Force F-16s and other fighters were scrambled and radio warnings broadcast but, with no response forthcoming, the fighters let off 80 warning shots during the first breach and 280 during the second. In a separate incident, two Russian Tu-95 bombers and two Chinese H-6 bombers flew for nearly 90 minutes within South Korea's air defense identification zone (ADIZ) in a manner that make it appear they were moving into formation. While there are a number of different points that could be addressed in this regard, I would like here to argue that, due to prolonged sanctions against Russia, the weakened nuclear arms control regime and the perpetuation of US-China disputes, military cooperation between Russia and China is progressing to a stage not seen before.

Russia's Ministry of Defense denied any "violation", but incursions by Chinese and Russian aircraft into South Korea's ADIZ at around the same time was by no means a coincidence. Having received a proposal agreed upon by Russia's Ministry of Defense and Ministry of Foreign Affairs, Prime Minister Dmitry Medvedev on July 18 signed a governmental directive in line with the Law on International Treaties to the effect that negotiations would be opened with China to reach an agreement on military cooperation (the Russian government's official archives portal site). This governmental directive did not stipulate when or where these negotiations would take place, nor did it list the areas of cooperation that would be the focus of these negotiations. However, Yuri Shvitkin, Deputy Chairman on the State Duma Committee on Defense, stated on July 22 that significant attention would be given to mutual military action and coordination, in addition to conventional forms of cooperation in joint military exercises and arms exports. On that same day, Frants Klintsevich, a member of the Federation Council's Committee on Defense and Security, commented that, in addition to technical cooperation, the agreement with China could entail the creation of an organization for mutual action on security issues and, in light of the extensive border shared by China and Russia, that Chinese use of the Russian Far East air defense system could bolster border security (RIA-Novosti, July 22, 2019). Furthermore, a source close to the Ministry of Defense reportedly suggested that the new agreement might enable more complex joint military exercises and patrol flights (Vedomosti, July 23, 2019).

The underlying factor most directly prompting China and Russia to seek new military cooperation is likely the August 2 expiration of the Intermediate-range Nuclear Forces (INF) Treaty. Although the US suggested in announcing its withdrawal that its action was driven by suspicions of treaty violations on Russia's part, it was more probably driven by the recognition that China and other countries were continuing to build up their medium-range missile capabilities even as the treaty banned the possession of such missiles by the US and Russia. With the treaty's cancellation, the US will gain a free hand to produce and deploy surface-launched intermediate-range missiles but, to counter China via these surface-launched intermediate-range missiles, it will need to deploy them in allied countries in Northeast Asia. Since the US and its allies have already begun deploying ballistic missile defense (BMD) systems, the termination of the INF Treaty will make it legal for the US to deploy surface-launched intermediate-range missiles under the protection of the BMD systems based in its Northeast Asian allies, a serious security concern for both China and Russia. While domestic public opinion within these allied countries and other factors make it unlikely for the time being that such missiles will actually be deployed, both China and Russia have begun to move toward military cooperation with the possibility in mind. To determine just how deeply committed the US is to defending its allies, this military cooperation may include military actions that will actually test the US' responses.

Given the historical mistrust between China and Russia, cooperative relations between China and Russia are frequently dismissed as being simply a "marriage of convenience" that lacks stability. China and Russia have certainly adopted different attitudes and approaches toward the US, depending on the issue at hand, and they are often not on the same wavelength in devising responses. It is also not the case that China and Russia are in full support of each other's diplomatic actions. Nevertheless, as long as the US-Russia and US-China disputes persist, it cannot be denied that China and Russia are two of very few powers able to share fundamental interests. It has been said that deeply-rooted mutual distrust would make it difficult for the two countries to pursue military cooperation down to the tactical level, but they are now looking to bolster their cooperation through agreement-based institution-building. An agreement may be limited in its ability to dispel mutual distrust, but the recent bomber flights do appear to have demonstrated that, for the moment, there is still potential for closer China-Russia military cooperation.
　
The need to include China in nuclear arms control has long been pointed out but, as China has not sought symmetry with the US in nuclear weapons capability, it would be no easy task to incorporate China into a framework of numerical restrictions aimed at achieving a quantitative balance premised on the bipolar structure of the Cold War. A new framework inclusive of China was discussed during the China-Russia summit meeting held on May 13 in Sochi, but Chinese Foreign Minister Wang Yi again rejected Chinese participation in such a framework, while Russian Foreign Minister Sergei Lavrov insisted that the US should engage in direct dialogue with China to discuss this matter. Russia respects China's position, and it has explicitly precluded any possibility that Russia would join with the international community to pressure China on arms control issues. Readying themselves for the strategic competition that will ensue with the end of the INF Treaty, both China and Russia are expected to continue and even accelerate their efforts to upgrade their military capabilities, and to highlight Japan's growing vulnerability through previously unimagined joint military action.

Japan needs to continue its diplomatic efforts to propose and emphasize multilateral negotiations on restricting intermediate-range nuclear forces at the Conference on Disarmament, the United Nations and other venues, and to seek out practical approaches to arms control and disarmament premised on asymmetry (e.g., installing/utilizing hotlines and otherwise building/bolstering crisis management frameworks, imposing limits on missile capabilities and numbers, implementing transparency measures, providing for advance notification of missile launches, and restricting deployment zones). At the same time, Japan will no doubt find it all the more imperative to strive for an appropriate balance between deterrence capabilities and arms control through its own defense efforts and through the Japan-US alliance.

This article is a reproduction of RIPS' eye No.238. (http://www.rips.or.jp/rips_eye/)