China’s SLBM Test Underscores the Importance of a Ballistic Missile Launch Notification Agreement

This 2026 test is the first time that China has ever launched a submarine-launched ballistic missile (SLBM) into international open waters and is the first time that Beijing has publicly demonstrated in the Indo-Pacific that China has a strategic nuclear strike capability launched from a nuclear-powered submarine. This is Beijing’s second launch of a ballistic missile in international waters since 1980. On September 25, 2024, China conducted a similar test launch of what was likely a land-based DF-31 ICBM into the Pacific Ocean. It is very difficult to determine whether this week’s test was a JL-2 or JL-3 missile with the photos that the PLA released. The only notable difference between the missiles is their dimensions and maximum range. Both missiles have the same number of stages and the same shape. The images that the PLA released are over open waters and do not provide any reference points against which to measure dimensions. This test covered 7,300 kilometers, which both the JL-2 and the JL-3 could reach. If this was a JL-2, then this missile was tested to nearly full range, whereas the JL-3 can travel over 10,000 kilometers.

Drivers of China’s SLBM Test

However, the timing and structure of this test indicate that it was anything but routine. There are likely several different political drivers for this particular test, as well as China’s desire to validate the capability of its military hardware.

First, China likely sought to use the missile test to showcase resolve and frustration at U.S. allies and partners. This Chinese missile test occurred the same day as Australia’s signing of a defense treaty with Fiji. Chinese media characterized this defense treaty as Australia seeking to shore up its influence in the South Pacific while also constraining Chinese power. Shortly after China launched its missile test, China’s Ministry of Foreign Affairs cautioned Australia and Fiji against using the defense treaty to target third parties (or China) or harm the interests of third parties. Australia’s defense pact with Fiji also comes on the heels of other Australian agreements, including with Vanuatu last week, to check Chinese military and economic activity in the region.

Second, China has demonstrated a repeated pattern of engaging in military exercises to counter U.S. or U.S.-led military activities around the same time. It is possible that China could be flexing its muscles against either the recently wrapped up Australian army exercise in 2026—Exercise Southern Jackaroo, which involved U.S. and Japanese forces—or the concurrent U.S.-led Rim of the Pacific (RIMPAC) naval exercises involving Australia, the Philippines, Japan, and over two dozen other U.S. allies and partners. Of note, the Philippine Coast Guard set a record this year by being the first foreign coast guard to participate in RIMPAC, which might be one of the reasons China’s missile test overflew parts of the Philippines.

Third, China has increasingly teamed up with Russia to engage in joint military exercises to counter U.S.-led military activities. Part of this is to signal that China also has its own friends and potential allies in a military contingency. The timing of the launch of the 13th China-Russia Joint Sea 2026 exercise to coincide with the SLBM launch is broadly consistent with China’s desire to portray Sino-Russian strategic alignment through coordinated military activities. Last month, for example, China and Russia engaged in a joint bomber patrol over the waters of the Sea of Japan, the East China Sea, and the western Pacific Ocean likely in response to the concurrent U.S.-led Exercise Valiant Shield. But what is curious this time is that China had two launch options for the missile—one from the Bohai Sea and another from the SCS—and launching from the SCS created more geographic distance from its military operations with Russia than if the missile test occurred from Bohai (Qingdao, the location of the China-Russia Joint Sea exercise is located in China’s Shandong province and very close to the Bohai Sea).

Finally, and technically, Beijing also seeks to use this SLBM launch to test the performance of its equipment. Chinese commentators, for example, speculate that the missile used was the JL-3, a new capability that China unveiled last year during its September 2025 military parade. It has undergone multiple different trials, and some argue that the JL-3 now needs to undergo a near-full flight trajectory to validate its performance and reliability. Regardless of whether China tested a JL-2 or a JL-3, the test will provide valuable data for China to improve its sea-based strategic nuclear strike capability.

The Need for a Ballistic Missile Launch Notification Agreement

China’s public messaging around this missile test indicates an effort by China to routinize testing in international waters. In the 2024 and 2026 launches, China notified the United States and some regional partners, but these notifications did not follow standard international procedures set forth in the Hague Code of Conduct against Ballistic Missile Proliferation (HCOC), which China has not ratified. In this week’s test, China provided mere hours of advance notice to the United States and Japan. It also provided about 23 hours of advanced notice to Australia and possibly other countries near the landing zone. In 2024, China provided less than 24-hour notice to the United States, Japan, Australia, New Zealand, and France. After that test, all five countries expressed disapproval over how the notifications were handled and publicly condemned China for not following the proper code of conduct.

China is the only major space-faring nation with ballistic missiles that remains entirely outside of the HCOC. If China claims that these tests are routine, then it is time that it undertakes responsible actions and follows the internationally established protocols for ballistic missile launch notifications. States that subscribe to the HCOC agree to exchange pre-launch notifications no less than 24 hours prior to launch to all 140 member states, including information about the launch area, direction of launch, and the general class of missile that is being tested.

For years, the international community has pressed Beijing to align with the HCOC. Since 2009, the United States, France, and the United Kingdom have consistently used the P5 process—the primary multilateral forum for nuclear-weapon states recognized by the Treaty on the Non-Proliferation of Nuclear Weapons—to lobby for China’s integration into the HCOC alongside broader strategic risk-reduction initiatives.

Diplomatically, Beijing has demonstrated great pride over its advance warnings and has attempted to leverage these notifications to garner diplomatic support. For example, during the 2026 Nuclear Non-Proliferation Treaty Review Conference, Chinese diplomats pointed to their 2024 advance notice as evidence of transparency and China’s commitment to strategic risk reduction in the national report and statements. In the 2026 test, the PLA claimed to have notified “relevant countries” in advance. Yet China’s ad-hoc and discretionary notification approach circumvents international procedures and has already drawn significant condemnation and criticism.

This lack of transparency is a feature, not a bug, of China’s nuclear forces. China is undergoing the largest qualitative and quantitative expansion of its nuclear arsenal ever, tripling the size of its nuclear arsenal from 200 weapons to over 600 in the last six years. China is constructing vast ICBM silos and expanding its missile inventory. Despite this massive buildup, China’s leadership has provided no formal notifications detailing how many weapons it plans to build. This structural opacity is a key aspect of China’s nuclear strategy, but it undermines international stability and contributes to nuclear arms racing dynamics. The global community thrives on transparency, consistency, and proactive confidence-building measures.

Testing ballistic missiles in international waters without following the proper protocols poses risks to the international community. This week’s missile launch, which came from the SCS, a protected bastion for Chinese ballistic missile submarines, mirrored a real missile attack in several ways. The test missile and dummy warhead flew in a realistic trajectory over thousands of kilometers and possibly crossed over Philippine territory. Tests such as these increase the chance of miscalculation. As a permeant member of the UN Security Council, China’s refusal to follow the HCOC also provides cover for other states—such as North Korea and Iran—to continue unrestrained testing without providing prelaunch notifications.

The HCOC has standardized ballistic missile launch notifications for over 24 years. Based on Chinese statements, the PLA intends to make open-ocean missile testing a routine component of its nuclear posture. There are no downsides to providing proper notice prior to future Chinese tests. Failing to adopt proper protocols risks an unintended global crisis.

Joseph Rodgers is deputy director and fellow with the Project on Nuclear Issues (PONI) in the Defense and Security Department at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Bonny Lin is director of the China Power Project and senior adviser at CSIS. Leon Li is a research associate with the China Power Project at CSIS.