China’s successful submarine-launched ballistic missile test into the southern Pacific this week was more than a routine military exercise. It provided Beijing with a rare opportunity to validate one of the most sensitive aspects of its nuclear deterrent its ability to command, communicate with and potentially deploy nuclear-armed submarines while remaining undetected.
The test, carried out on Monday, involved a ballistic missile launched from a strategic nuclear-powered submarine and has drawn close scrutiny from regional governments and defence analysts. While Chinese officials described it as a standard military drill conducted in accordance with international law, experts say it marks another step in China’s effort to build a more credible and survivable nuclear force.
Why submarine missile tests matter
Unlike land-based nuclear missiles, submarine-launched ballistic missiles (SLBMs) are designed to ensure a country can retaliate even if its territory comes under nuclear attack. This “second-strike capability” forms one of the central pillars of nuclear deterrence.
Analysts say the test was not solely about assessing missile performance. It also allowed Chinese military leaders to evaluate the complex command-and-control systems needed to operate nuclear submarines while they remain hidden beneath the ocean.
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Maintaining secure communications with submarines without revealing their position is among the most technically demanding aspects of any nuclear arsenal.
Collin Koh, a security expert at Singapore’s S. Rajaratnam School of International Studies, said Beijing would likely have been evaluating communications, operational procedures and submarine performance alongside the missile itself.
A key part of China’s nuclear modernization
Regional defence experts believe the missile was launched from one of China’s Type-094 nuclear-powered ballistic missile submarines (SSBNs), although Beijing has not officially identified the vessel.
China has steadily expanded its nuclear capabilities over the past decade, developing what military planners describe as a complete “nuclear triad”—the ability to launch nuclear weapons from land, sea and air.
The submarine component is viewed as increasingly important because it offers a survivable retaliatory force if China’s land-based missile sites were destroyed during a conflict.
According to previous U.S. defence assessments, China has already begun near-continuous deterrence patrols using its SSBN fleet, joining the United States, Russia, Britain and France in maintaining an at-sea nuclear capability.
Challenges remain
Despite the progress, experts note that China’s submarine force still faces significant operational hurdles.
To threaten the continental United States with its most advanced JL-3 submarine-launched missile, Chinese submarines would likely need to leave the relative protection of the South China Sea and enter the wider Pacific Ocean, where they could be tracked by U.S. and allied anti-submarine forces.
Military analysts say American and allied navies closely monitor Chinese submarines using surveillance aircraft, underwater sensor networks and naval patrols.
China is also developing a quieter next-generation ballistic missile submarine that could improve its ability to operate undetected.
Regional reaction
The launch prompted criticism from several regional governments.
The United States said China had provided only limited advance notification before the launch and expressed concern over Beijing’s rapidly expanding nuclear arsenal. Japan, Australia, New Zealand and Taiwan also voiced concern following the test.
China rejected the criticism, insisting the exercise complied with international law and was intended solely to safeguard national security and strategic stability.
Beijing has repeatedly argued that its nuclear modernization remains defensive and consistent with its longstanding policy of not being the first to use nuclear weapons.
Analysis: A signal beyond the missile
The importance of this test extends beyond the missile itself. It demonstrates Beijing’s growing confidence in the sea-based leg of its nuclear deterrent, an area traditionally dominated by the United States and Russia.
The exercise also reflects China’s broader military modernization strategy under President Xi Jinping, which prioritizes survivable nuclear forces capable of guaranteeing retaliation under any scenario. Even if operational challenges remain—particularly the ability of Chinese submarines to evade increasingly sophisticated Western tracking systems—the test suggests China is moving closer to a fully credible second-strike capability.
Strategically, the launch sends multiple messages. Domestically, it showcases advances in China’s military technology. Regionally, it reinforces Beijing’s determination to protect its security interests. Internationally, it signals that China’s nuclear forces are becoming more sophisticated, mobile and resilient, adding another layer of complexity to strategic competition with the United States and its allies in the Indo-Pacific.
With information from Reuters.
