Hong Kong: China's submarine-fired ballistic missile test into the southern Pacific on Monday gave its military leadership an opportunity to examine some of the most complex and sensitive operations of its evolving nuclear deterrent, analysts and diplomats say. Commanding, controlling and communicating with nuclear-armed submarines attempting to operate undetected pose immense challenges, they say - something felt acutely by a Chinese Communist Party leadership where the military's political loyalty is paramount.Also Read: How Taiwan's US$1.4 billion radar detected and tracked China's ballistic missile "This aspect is certainly something that would have been very much evaluated, besides looking at the actual technical capabilities of the missile and submarine," said Collin Koh, a security scholar at Singapore's S. Rajaratnam School of International Studies. "There are still challenges ahead but it would seem they are getting close to an operational strike capability here...they are probably trying to demonstrate that even if they can't ‌get into a position to ⁠hit the ⁠continental U.S., they could still target Guam and Hawaii." China's test firing of the missile armed with a dummy warhead drew criticism from regional powers, with the U.S. saying it was an intercontinental ballistic missile that landed in the southern Pacific Ocean. Chinese state media and officials described the test as a "routine" military drill that was not directed at a specific target or country, and was handled professionally. The Chinese defence ministry did not immediately respond to questions from Reuters. It was China's most significant long-range ballistic missile test since September 2024, when the People's Liberation Army fired a weapon into the southern Pacific Ocean from a mobile launcher on Hainan Island in the South China Sea.China's submarines key to nuclear strategy Monday's missile was fired from one of China's six Type-094 nuclear-powered submarines known as SSBNs, said analysts and academics. State media said it was a strategic missile submarine (SSBN), but did not identify the class. An SSBN is a large ⁠nuclear-powered submarine ‌designed to launch nuclear-armed intercontinental ballistic missiles. Regional military attaches and analysts say China's SSBN operations, based out of Hainan Island, are among the most closely watched elements of its ongoing military modernisation, given their importance to China's nuclear deterrent to ensure a second-strike capability. If its nuclear-armed submarines can operate undetected, China can strike back ⁠if its more extensive land-based weapons are destroyed in a first strike by an adversary. This is widely seen as a particularly important factor for Beijing, which still maintains an official policy that it would not be the first to use nuclear weapons in a conflict. The U.S. and its allies at times attempt to track Chinese submarines through naval vessels, networks of underwater sensors in key chokepoints, as well as air patrols with P-8 Poseidon aircraft, which are equipped with advanced maritime surveillance devices, military attaches and analysts say. Such operations are expected to increase as China's capabilities grow. A Pentagon report in 2022 stated that China had begun operating near-continuous deterrence patrols with its SSBNs. The U.S., Russia, France and Britain have for decades routinely deployed such a nuclear strike capability, and India is now developing its own SSBNs. A study of China's nuclear weapons released this week by the Bulletin of the Atomic Scientists, a Chicago-based research organisation, said that while U.S. officials have ‌not publicly stated that China's SSBNs were actually armed with nuclear weapons on such patrols, some U.S. officials have said it to the authors privately. Noting the lack of official confirmation, the study says that "President Xi Jinping's purge of military officials - including leaders of the People's Liberation Army's rocket force - make it seem unlikely that nuclear warheads would be handed over to the military under ⁠normal circumstances".China's 'nuclear triad' While the exact location of Monday's submarine missile launch and the precise missile used have also yet to be confirmed, the ability of China's SSBNs to manoeuvre undetected beyond its coasts is also likely to be closely scrutinised. The Type-094 submarine will eventually be replaced with a more advanced, quieter version now under development, analysts say. To reach the continental United States with its most advanced submarine missile, the JL-3, a submarine would have to move beyond the South China Sea into the western Pacific, potentially risking exposure to rival navies. The JL-3, which is believed to be armed with multiple warheads and was showcased in a military parade in Beijing in September 2025, has a range of 10,000 km (6,214 miles). Despite the unknowns, China's Global Times newspaper has said the missile launch showed how China was continuously strengthening its "nuclear triad" of strategic forces - the ability to fire nuclear weapons from land, sea and the air. "This will compel external powers and their followers to abandon attempts aimed at forcing Chinese concessions through maximum military pressure or pre-emptive strikes, thereby fundamentally reducing the risk of large-scale conflict...," the Global Times editorial said.