- Nuclear Triad means the capability of delivering nuclear weapons by aircraft, land based ballistic missiles and submarine launched missiles.
- India declared that its nuclear triad is operational after indigenous Ship Submersible Ballistic
- Nuclear (SSBN) INS Arihant achieved a milestone by conducting its first deterrence patrol.
- India has put in place a robust nuclear command and control structure, effective safety assurance architecture and strict political control, under its Nuclear Command Authority.
- INS Arihant, which is equipped with nuclear-tipped ballistic missiles completed a nearly month-long nuclear deterrence patrol.
- INS Arihant will enable India to assert its rights on water, besides land and air.
- It now joins a small group of countries — the United States, Russia, China, France and the United Kingdom — that have this capability.
- Arihant’s successful nuclear deterrence patrol signifies India’s attainment of complete mastery over all the highly complex systems and procedures.
- India’s nuclear deterrence 20 years after the country went nuclear is now secure as it rests on a triad of land, air and undersea vectors.
- The success of INS Arihant enhances India’s security needs. Given India’s ‘No-First-Use’ (NFU) in launching nuclear weapons, the SSBN is the most dependable platform for a second-strike.
- SSBNs are designed to prowl the deep ocean waters and carry nuclear weapons.
- Because they are powered by nuclear reactors, these submarines can stay underwater indefinitely without the adversary detecting it.
- The other two platforms — land-based and air-launched are far easier to detect.
- It demonstrates that India, apart from its capability to deliver nuclear weapons both from land and
- from air, can now also do so from under water.
- It provides the ultimate credibility to nuclear deterrence.
- It sends out an unambiguous message that nuclear blackmail will not work.
- The nuclear deterrence patrol signifies India having come off age as a mature nuclear-armed state.
- This exercise is testimony to India’s technological prowess.
- It shows a high degree of engineering skill and workmanship with substantial indigenous component
- The Arihant is the lead ship of India’s Arihant class of nuclear-powered ballistic missile submarines.
- These will form a potent and formidable weapons system which will ensure national security.
- Arihant is India’s first indigenously designed and built nuclear-powered submarine.
- Arihant is armed with K-15 Sagarika missiles with a range of 750 km.
- It will carry the longer 3,500 km range K-4 missiles being developed by the Defence Research and Development Organisation (DRDO).
- This is the longest in the Navy’s fleet of submarines.
- The second submarine in the series, Arighat is now undergoing sea trials after which it will be inducted into service.
INS Arighat is an upgraded variant of the Arihant-class submarine.It is the second nuclear-powered ballistic missile submarine being built by India. under the Advanced Technology Vessel (ATV) project to build nuclear submarines at the Ship Building Centre in Visakhapatnam.
In March 2019, India and Russia signed a deal for the lease of another Akula-class nuclear submarine to India for 10 years. The new vessel, called the Chakra-III, will be delivered to the Indian Navy by 2025.
The Arihant-class (Sanskrit, for Slayer of Enemies) is a class of nuclear-powered ballistic missile submarines being built for the Indian Navy. They were developed under the ₹90,000 crore (US$13 billion) Advanced Technology Vessel (ATV) project to design and build nuclear-powered submarines. These vessels are classified as ‘strategic strike nuclear submarines’ by India
The Indian Navy currently operates fourteen diesel powered submarines and two nuclear powered submarines. India’s submarine fleet is based at two locations: Visakhapatnam on the east coast and Mumbai on the west coast. 
Capabilities at a Glance
- Total Submarines in Fleet: 16
- Ballistic Missile Submarine (SSBNs): 1
- Nuclear-Powered attack submarines (SSNs): 1
- Diesel-electric attack submarines (SSKs): 14
- Air-independent propulsion (AIP) enabled: 0
While India discussed the potential of nuclear-powered submarines as early as the 1960s, it didn’t begin the development of its Advanced Technology Vessel (ATV) submarine program until 1983. (source) The ATV is a part of India’s sea-based nuclear deterrent, which is one of the three legs of India’s triad of airborne, naval, and land-based platforms as a minimum nuclear deterrent (MND). IModernization and Current Capabilities
India’s nuclear-powered submarine program is under the management and operations (M&O) of the Defence Research and Development Organisation (DRDO), the Department of Atomic Energy (DAE), and the Indian Navy at Visakhapatnam.India took steps to operationalize its nuclear triad by commissioning its first ATV submarine, the INS Arihant, in August 2016.
India is currently constructing two new submarine bases. The first is Karwar, located 500 kilometers south of Mumbai.  The second is a secret naval base called the INS Varsha. This base is on the east coast near Kakinada and will have underground pens for the submarines.