Judging from the style of the US, there are multiple calculations behind the recent quadrilateral joint military drill.

First, it takes the opportunity to put pressure on China. Prior to the drill, the Philippines had already carried out multiple illegal intrusions into China’s islands and reefs in the South China Sea. The US attempts to use the joint military drill to intensify its efforts to cheer and support the Philippines and encourage the Philippines to continue making trouble for China in the South China Sea.

Second, it aims to help Biden win re-election. The US presidential election is about to kick off in November 2024, but the external situation is unfavorable to Biden. The Ukraine crisis has formalized the confrontation between the US and Russia, and the latest round of Palestinian-Israeli conflict not only makes the US more vulnerable in the Middle East, but also augurs the worrying prospects of Petrodollar. The Red Sea crisis shows that the US maritime advantages are being eroded. In this context, Biden urgently needs a geopolitical "victory", even if it is a symbolic one.

Third, it takes the opportunity to strengthen control over its allies, especially Japan. At present, only a few powerful countries can arm the army, navy, and air force with advanced technology. Due to the lack of necessary electronic terminals, coupled with the complexity and high cost of conventional warfare, it is impossible for middle powers to develop all weapons for three-dimensional warfare on land, sea and air. The US is undoubtedly one of the few powerful countries, but Japan, Australia, and the Philippines are not. Through military drill, the US can make the navies of Japan, Australia and the Philippines accept US war tactics and thus strengthen its control over these countries.

The characteristics of this joint military drill also deserve particular attention.

First, the subjects of the drill are highly targeted. According to sources, this was the first comprehensive drill among the four countries, focusing on anti-submarine warfare, ship communications, and formation navigation training. The four countries also held a joint replenishment-at-sea training drill in August 2023, but their sailors only exchanged salutes and took group photos. It can thus be seen that naval cooperation among the participating countries has begun to shift from symbolic meaning to practical operations, and there is a trend of joint anti-China attempts.

Second, the participating troops convey multiple signals. According to Nikkei Asia and Kyodo News of Japan, five military vessels including two Philippine warships–Del Pilar-class and BRP Ramon Alcaraz patrol vessels, USS Mobile littoral combat ship (LCS), Japanese destroyer Akebono and Australian frigate HMAS Warramunga participated in the drill. The presence of the USS Mobile indicates that the US believes that future disputes over maritime rights between China and the Philippines will still be conducted near Chinese islands and reefs. Japan's Akebono destroyer is a Murasame-class general-purpose destroyer with strong anti-submarine capabilities and is equipped with an Active Phased Array Radar (APAR), which shows that the Japan Self-Defense Forces (JSDF) will strengthen its anti-submarine warfare capabilities and reconnaissance capabilities in the South China Sea. The Warramunga frigate is Australian Navy's second-largest surface destroyer after the Canberra class amphibious assault ship and Hobart class destroyer. The participation of Warramunga shows that Australia attaches great importance to this drill.

Third, the drill concept is highly targeted. The maritime disputes between China and the Philippines are still ongoing, and the military drill conducted by the US, Australia, Japan, and the Philippines are self-evidently aimed at China.

This military drill will have serious consequences. It will exacerbate the already prominent maritime disputes between China and the Philippines and complicate the maritime security situation in the South China Sea. In addition, the malicious interference in regional affairs by the US and other countries outside the region may set a bad precedent and destabilize the situation in the South China Sea.

(The authors are Yang Zhen and Guoyao, respectively deputy director of the Northeast Asia Research Center, Shanghai University of Political Science and Law and a student at the National University of Defense Technology of the Chinese People's Liberation Army.)

Editor's note: Originally published on china.com.cn, this article is translated from Chinese into English and edited by the China Military Online. The information and opinions in this article do not necessarily reflect the views of eng.chinamil.com.cn.