India has successfully tested the K-4 submarine-launched ballistic missile (SLBM) from INS Arighaat in the Bay of Bengal, marking a major milestone in strengthening the sea-based leg of India’s nuclear deterrence.
The test was conducted off the coast of Visakhapatnam, though no official statement was issued by the Ministry of Defence.
K-4 SLBM Test from INS Arighaat Boosts India’s Nuclear Deterrence
K-4 Missile and Strategic Significance
According to defence sources, the missile tested was the solid-fuelled K-4, capable of:
- Range: ~3,500 km
- Payload: Up to 2 tonnes, including nuclear warheads
The K-4 missile is critical for operationalising India’s sea-based nuclear deterrent, enhancing the credibility of the country’s nuclear triad (land, air, and sea-based delivery systems).
As with all submarine-launched ballistic missiles, multiple trials are required before full operational deployment, and a detailed technical evaluation will determine whether all mission objectives were achieved.
Role of INS Arighaat in India’s Nuclear Triad
INS Arighaat is India’s second nuclear-powered ballistic missile submarine (SSBN) and is operated by the Strategic Forces Command.
Key details:
- Commissioned on August 29 last year
- Displacement: 6,000 tonnes
- Part of the Advanced Technology Vessel (ATV) programme
INS Arighaat follows INS Arihant, which became fully operational in 2018 but is limited to K-15 missiles with a range of 750 km.
The recent K-4 launch marks the first such test from INS Arighaat, after earlier K-4 trials conducted from submerged pontoons.
Future SSBNs and Missile Development
India plans to further expand its SSBN fleet under the ATV programme:
- INS Aridhaman – Expected commissioning: Q1 2026
- Fourth SSBN – Expected by 2027–28
- Next-generation SSBNs will displace around 7,000 tonnes
- Long-term plans include 13,500-tonne SSBNs with more powerful nuclear reactors
On the missile front:
- K-4 will be followed by K-5 and K-6 SLBMs
- Expected range: 5,000–6,000 km
- These developments will significantly narrow the strategic gap with major nuclear powers
India’s Nuclear Deterrence Posture
While India’s land-based missiles like Agni-5 and air-delivered nuclear capabilities are well established, SSBNs provide the most survivable and secure second-strike option.
The induction of K-4-equipped submarines greatly enhances India’s second-strike capability, reinforcing its doctrine of credible minimum deterrence under the declared “No First Use” nuclear policy.
Exam-Oriented Key Facts
- K-4 is a submarine-launched ballistic missile with ~3,500 km range
- Test conducted from INS Arighaat
- INS Arighaat is India’s second SSBN
- Operated by the Strategic Forces Command
- Part of the Advanced Technology Vessel programme
- SSBNs are the most survivable leg of a nuclear triad
- India follows a No First Use nuclear doctrine
Question & Answer
Q1. Which missile was recently tested from INS Arighaat?
(a) K-15
(b) K-3
(c) K-4
(d) Agni-5
Answer: K-4
Q2. INS Arighaat belongs to which category of naval vessels?
(a) Nuclear-powered attack submarine
(b) Aircraft carrier
(c) Nuclear-powered ballistic missile submarine
(d) Destroyer
Answer: Nuclear-powered ballistic missile submarine
Q3. What is the approximate range of the K-4 missile?
(a) 750 km
(b) 1,500 km
(c) 2,000 km
(d) 3,500 km
Answer: 3,500 km
Q4. Which organisation operates India’s SSBN fleet?
(a) Indian Navy Western Command
(b) Strategic Forces Command
(c) Defence Research and Development Organisation
(d) Integrated Defence Staff
Answer: Strategic Forces Command
Q5. Which doctrine governs India’s use of nuclear weapons?
(a) First strike doctrine
(b) Massive retaliation
(c) Flexible response
(d) No First Use
Answer: No First Use
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