India has re-issued a Notice to Airmen (NOTAM) on December 18, 2025, for a likely sea-launched missile test in the Bay of Bengal, establishing a no-fly zone spanning approximately 3,240 kilometers from December 22 to 24. This follows earlier notifications for tests in December, including expanded zones up to 3,550 km for December 17-20, amid vigilance against Chinese surveillance vessels probing Indian waters. The trial, potentially involving the K-4 submarine-launched ballistic missile (SLBM) from Arihant-class submarines off Visakhapatnam or Odisha’s Chandipur, validates India’s robust second-strike nuclear triad capabilities. Conducted by DRDO and the Indian Navy, it reinforces national deterrence in the Indo-Pacific, ensuring survivability against regional threats while prioritizing aviation and maritime safety.