India’s Sea‑Based Nuclear Deterrent Expands Gap with Pakistan

India has likely begun deploying nuclear warheads on its fleet of ballistic‑missile submarines (SSBNs), marking the first time a side in the South Asian nuclear rivalry has placed nuclear weapons at sea. The Stockholm International Peace Research Institute’s 2026 yearbook notes that a small number of warheads may already be loaded on a single SSBN conducting occasional deterrence patrols.

Pakistan lacks a submarine capable of carrying such weapons and has no realistic timeline for acquiring one, leaving it without a sea‑based nuclear response. The disparity is widening the subcontinent’s deterrence architecture, reshaping strategic calculations since Pakistan first tested a nuclear device in 1998. India’s SSBN fleet now includes the commissioned INS Arihant, the newer INS Arighat equipped with K‑4 missiles (range 3,500 km), and additional vessels slated to join by 2027, enabling continuous patrol rotations.

Analysts say the opacity of India’s under‑sea operations makes the vessels difficult to target, further strengthening India’s second‑strike capability while Pakistan remains without an equivalent deterrent.