India and China have been engaged in a tense cat-and-mouse game in the Bay of Bengal since late November, with New Delhi repeatedly issuing and then cancelling missile test notifications while Beijing deployed up to five research vessels to monitor Indian military activities.

Since the last week of November, India has issued three Notices to Airmen (NOTAMs) only to cancel them at the eleventh hour. On December 16, India issued its latest notification for December 22-24, establishing a 3,240-kilometre test corridor over the Bay of Bengal, a zone suggesting a possible test of the nuclear-capable K-4 submarine-launched ballistic missile.

As India made each announcement, China flooded the region with research vessels. The Lan Hai 101 entered the Indian Ocean in early December, joining at least four other Chinese vessels already active near the region, including Shi Yan 6, Shen Hai Yi Hao, and Lan Hai 201. On December 14, a fifth vessel, Da Yang Yi Hao, capable of ocean floor and mineral research, entered the Indian Ocean Region.

Deliberate Strategy or Weather Delays?

Defence experts suggest India may be deliberately testing Chinese response capabilities. "Using stage-wise expansion of NOTAM zones disrupts Chinese positioning. Once the Chinese vessels arrive and position themselves, India cancels or withdraws the NOTAMs abruptly, rendering the deployments futile," defence analyst Sandeep Unnithan told India Today.

Former Indian Navy officer Abhijit Singh noted the timing of China's deployments was "more than incidental." "Their repeated presence near Indian missile test zones suggests an interest in gathering data related to the submarine launch environment," Singh told The South China Morning Post.

The pattern echoes a November 2022 incident when India cancelled a missile test at the last minute after the Chinese research vessel Yuan Wang 06 entered the Indian Ocean.

K-4 Missile in Focus

The K-4 missile, with a 3,500-kilometre range, can strike targets across much of Pakistan and significant parts of China. India last tested the K-4 in November 2024 from the newly inducted nuclear submarine INS Arighaat, marking the first operational launch from that vessel.

These Chinese vessels are widely believed to be dual-use platforms carrying equipment for both scientific research and sophisticated tracking and telemetry systems. China can use collected data to model next-generation stealth submarines and anti-submarine warfare capabilities.

India has kept the region on edge with back-to-back notifications. On December 5, India also issued an alert for an Air Force exercise in the Arabian Sea, uncomfortably close to Pakistan's Karachi, just 200 nautical miles away. Whether the December 22-24 test proceeds or joins the list of cancelled NOTAMs remains to be seen.