A submarine-launched ballistic missile test by China into the South Pacific has triggered widespread alarm in the Indo-Pacific region. While countries periodically test missiles, Beijing’s testing has triggered alarm bells in the region. Why is a submarine test significant and why the panic?

In a display of its growing military capabilities, China’s navy test-launched a long-range, nuclear-capable ballistic missile from one of its nuclear-powered submarines into the South Pacific. According to state-run news agency Xinhua, a submarine of the People’s Liberation Army (PLA) Navy on Monday fired the missile, carrying a dummy warhead, toward international waters in the Pacific. The launch marks only the third time China has publicly acknowledged conducting such a test, after similar announcements in 1980 and 2024, and has raised concerns across the Indo-Pacific.

“The test launch complies with international law and international practice, and is not directed at any specific country or target,” Xinhua quoted the PLA as saying. It added that the navy had notified “relevant countries” in advance of the launch.

According to Xinhua, the dummy warhead “landed precisely within the designated waters,” indicating that it struck the area that had been identified beforehand to the notified parties. News agency Reuters reported that Chinese Foreign Ministry spokesperson Mao Ning said on Monday that the launch was conducted “safely, in a standardised and professional manner throughout,” adding, “We hope relevant countries will not over-interpret the matter.”

However, the missile test did spread panic in the Indo-Pacific region. There are several reasons for that. Some countries complained of the short notice from Beijing ahead of the test being conducted. Another reason is China’s image and its territorial disputes with its neighbours. While missile tests aren’t unusual, we have a look at why the one by Beijing triggered alarm bells.

WHAT WAS THE MISSILE CHINA TESTED FROM SUBMARINE?

Even though Beijing is claiming that it had informed all relevant countries about its missile test well in advance, and that the test targeted no particular nation in particular, the news has still sparked considerable alarm among its neighbours.

While China has not revealed exactly what missile it test-launched, state-controlled tabloid Global Times, citing a military expert, said it was likely to have been the JL-3, China’s most advanced submarine-launched missile, which debuted at a military parade last year.

Joseph Wu, the secretary-general of Taiwan’s National Security Council, meanwhile claimed in a statement on X that Beijing launched a JL-2 Submarine Launched Ballistic Missile.

“The PRC tested a JL2 SLBM flying over the Philippines moments ago. It’s a provocation that destabilises the Indo-Pacific. China just proved itself again to be a bully on the block,” Wu wrote on X.

WHY CHINA’S NEIGHBOURS RAISED ALARM OVER MISSILE TEST

According to a report in Reuters, the governments of New Zealand, Australia, New Zealand and Japan claimed that they were informed by China only hours beforehand and noted that the missile was fired into the South Pacific Nuclear Free Zone. The Zone was established by the 1986 Treaty of Rarotonga, which prohibits nuclear weapons throughout the region. China ratified the protocols in 1987, pledging not to test nuclear weapons within the zone or threaten to use them against any country in the region.

“It appears that despite our long-standing concerns about this type of activity, China carried out the test within hours of informing us,” Foreign Minister Winston Peters told news agency, The Associated Press (AP) in a statement. Reuters further reported Peters as stating, “We, like our neighbors in other Pacific countries, have no interest in China using the South Pacific as a testing site for missile capability.”

Australia’s Foreign Minister, Penny Wong, said the test was “destabilising” for the region.

“Australia has been clear with China that we regard this as destabilising to the region,” Australia’s Foreign Minister Penny Wong told reporters in Fiji on Monday, reported AP. Wong had been in the island nation to sign a mutual defence treaty meant to counter Chinese influence in the Pacific.

US SLAM CHINA’S MISSILE TEST OVER OPAQUE N-PROGRAMME

Japan also voiced concern, urging Beijing to “rethink” its missile testing. “China’s military activities, combined with its lack of transparency, have become a grave concern for Japan and the international society,” Chief Cabinet Secretary Minoru Kihara was quoted as saying by AP.

The US also criticised the launch, saying it reflected growing concerns over China’s expanding nuclear arsenal. US State Department spokesperson Thomas Pigott was quoted by AP as saying that while America was “working harder than ever” to prevent nuclear proliferation, China was moving in the opposite direction.

“Beijing’s rapid and opaque nuclear weapons build-up is of great concern to the region and the world,” he said. Pigott added that the US would continue to urge Beijing to engage in meaningful arms control discussions and commit to a regularised notification arrangement for intercontinental ballistic missile and space launches.

CHINA SEEN AS EXPANSIONIST, HAS TERRITORIAL DISPUTES

Over the decades, China has built an image of an expansionist because of its territorial disputes and programmes like the Belt and Road Initiative (BRI).

Beijing has engaged in maritime and land border conflicts with nearly all of its neighbours.

For years, Beijing has asserted expansive sovereignty over virtually the entire South China Sea via its controversial “nine-dash line”, which directly overlaps with the exclusive economic zones of Vietnam, the Philippines, Malaysia, and Brunei.

On land, one of the examples of Chinese expansionism is Tibet. China didn’t share land borders with India, but the situation changed after it annexed Tibet in 1951. Since then, India and China have witnessed multiple border stand-offs.

Most of China’s neighbours perceive it as hostile and a destabilising presence. That is the reason why a missile test by it can trigger alarm bells.

WHY IS A SUBMARINE MISSILE TEST SO SIGNIFICANT?

The exact purpose of China’s Submarine Launched Ballistic Missile (SLBM) test launch isn’t clear. However, a Pentagon report published in 2024 (the last time China had test-launched a SLBM) had claimed that tests of this nature were “probably to practice a wartime nuclear deterrence operation during peacetime and validate its ability to deliver a nuclear weapon to full range”.

The SLBM test-firing comes as China continues to rapidly expand both its conventional and nuclear weapons arsenals. China has a fleet of six ballistic-missile submarines and 59 nuclear-powered attack submarines, according to the Nuclear Threat Initiative, a Washington-based think tank.

In its latest report to Congress on China’s military capabilities, released in late 2025, the Pentagon said China has an estimated stockpile of around 600 nuclear warheads in 2024, adding that the PLA remains on track to field more than 1,000 nuclear warheads by 2030.

In 2025, China increased the number of deployed nuclear warheads to 34 from 24 in 2024, according to a report by Sipri, a Swedish think tank on conflict, armaments, and arms control.

While it’s not fully clear the exact missile used, reports suggest it is either the JL-2 SLBM, or the newer JL-3 SLBM. The JL-2 is reported to have a range of about 7,200 km, while the JL-3, which boasts a reported range of about 10,000 km can strike parts of the continental US from Chinese coastal waters.

What makes SLBMs, like the one test fired by China, particularly significant is that it gives countries a viable “second-strike” option, or the ability to launch retaliatory strikes even after suffering devastating nuclear strikes. This is because, unlike land-based launchers that can be tracked and air-launched platforms that can be shot down, nuclear submarines are significantly more difficult to track.

The latest test also reaffirms China’s status as a credible nuclear triad power, that being the ability to deliver nuclear weapons from land-based missiles, strategic bombers, and submarine-launched ballistic missiles. Besides China, only the US, Russia, the UK, France and India possess operational nuclear triad capabilities.

While the test reinforces China’s capabilities, it has triggered panic in the Indo-Pacific region. That has to do with Beijing’s projection of power and its expansionist image.