India is finally close to operationalising its long-awaited nuclear weapons triad--the capability to fire nukes from land, air and sea. Although the land-based Agni ballistic missiles as well as fighter bombers configured to deliver nuclear weapons have been available for long, the triad's missing third and most potent sea leg has been a big operational gap till now.
The country's first indigenously-constructed nuclear submarine INS Arihant (which means annihilator of enemies), propelled by an 83 MW pressurised light-water reactor at its core, was commissioned into service in August after extensive sea trials since December 2014.
INS Arihant's 750 km and 3,500 km missiles may be somewhat dwarfed by SLBMs (submarine-launched ballistic missiles) with ranges of well over 5,000 km with the US, Russia and China, but the completion of the nuclear triad is critical for a country like India with a clear declared policy of “no first-use“ of nuclear weapons.It makes its second strike capability much more credible.
A pre-emptive enemy strike can conceivably take out a rival's nuclear missiles and fighter bombers. That is why an SSBN, capable of prowling under water for months without being detected, is considered the most effective and deadly platform for a retaliatory nuclear strike.
The 6,000-tonne submarine is, however, “not yet fully ready“ to be deployed for “deterrent patrols“ with nuclear-tipped ballistic missiles in its four silos. INS Arihant has undergone a whole host of surface and “dived“ sorties during its trials to prove its sea-worthiness. But the full weapons integration with the “K“ (named after former president APJ Abdul Kalam) series of SLBMs will take some more time. While the K-15 SLBM has a 750-km range, the K-4 can go up to 3,500-km.
INS Arihant is the first of three such SSBNs (nuclear-powered submarines with long range nuclear ballistic missiles) being constructed under the secretive ATV (advanced technology vessel) programme launched decades ago. The construction of the second one, INS Aridhaman, is also almost complete now, with its delivery slated for 2018.
Apart from both Pakistan and China having largely ambiguous nuclear weapons policies, the growing presence of Chinese nuclear submarines in the Indian Ocean region has become a major source of concern for the Indian security establishment over the last couple of years. The criticality of SLBMs for deterrence can be gauged from the fact that even the US and Russia are ensuring that almost two-thirds of the strategic warheads they eventually retain under strategic arms reduction agreements are such missiles.
India does currently operate a nuclear-powered submarine INS Chakra, acquired on a 10-year lease from Russia, while negotiations are underway to acquire another such vessel soon. These submarines do have conventional cruise missiles and other weapons but are not armed with nuclear missiles because of international treaties. Only INS Arihant can complete India's nuclear triad.