Deterrence from Depth: SSBNs in India’s Nuclear Strategy

India’s sea-based nuclear deterrent is entering a new phase, with the third Arihant-class SSBN, INS Aridhaman, due for commissioning and a fourth boat at an advanced stage of construction.Together, this expanding force is intended to form the ultimate guarantor of India’s nuclear deterrence.The credibility and perceived invulnerability of these platforms are therefore sine qua non for deterrence stability. Against this backdrop, the book examines the optimal deployment strategies India might adopt to enhance the survivability of its SSBNs.The principal strategy is open-ocean patrols, while an alternative approach is the bastion strategy, under which SSBNs operate within relatively secure home waters.Both strategies can be operationalised through continuous at-sea deterrence, with at least one submarine maintained on patrol at all times to strengthen the credibility of assured retaliation.Each approach carries distinct advantages and limitations.Accordingly, the book analyses the experi