With India's defence forces possessing nuclear strike capabilities from land and air, the triad will be completed by the end of this financial year when the navy acquires a nuclear submarine from Russia.
INS Chakra, the first-generation Russian Nerpa Akula II class nuclear submarine, armed with 300-km range Klub missiles, is to be berthed in the Bay of Bengal. The leased 8,100-tonne vessel is currently in the final user acceptance trial stage in northern Russia.
Indigenous nuclear submarine INS Arihant is also on track, with sea trials planned over the next six months. The submarine is to be commissioned next year, making the Indian Navy a formidable force in the Indian Ocean and beyond.
The underwater pontoon tests for test-firing of longer range submarine-launched nuclear missiles have already been completed.
Top government sources said the three-phase technical user acceptance trial for the Akula II submarine has already begun.
Though the submarine was to join the Indian Navy in 2009, there was a delay due to a mishap during sea trials in which 20 submariners lost their lives in a conflagration.
While Captain Ashokan will be the first commanding officer of INS Chakra, Captain Sanjay Mahendru will be the commanding officer of INS Arihant.
Both submarines will be based in eastern seaboard in Visakhapatnam, with the Gulf of Thailand and the South China Sea being within operational range.
The nuclear submarine project was reviewed and discussed by defence minister AK Antony during his visit to Russia from October 3-5.
After returning from the East Asia Summit in Bali and Singapore on November 20, national security advisor Shiv Shankar Menon flew to Russia the next day to review the bilateral projects and prepare for the India-Russia summit on December 16.