India has for the third time signed an agreement to lease a Russian Akula-class nuclear-powered attack submarine according to Times of India. New nuclear-powered attack submarine (SSN), will be available by 2025, after a comprehensive refurbishment at a Russian shipyard. The agreement will be realised despite the threat of US financial sanctions looming over the earlier $5.4 billion contract inked for Russian S-400 Triumf missile systems in October last year.

This submarine will replace INS Chakra, the Akula class submarine taken on a 10-year lease from Russia in April 2012. INS Chakra, is not equipped with long-range nuclear missiles due to international treaties.

Though India is hopeful of eventually getting US presidential waiver for the S-400 deal, even as New Delhi and Moscow are finalising an alternate payment mechanism, the new submarine deal could complicate matters.

India’s deal for the new SSN, however, will further raise the hackles of US, which under its new law CAATSA (Countering America’s Adversaries through Sanctions Act) seeks to prevent countries from buying Russian weapons or Iranian oil.

Nuclear-powered submarines can stay submerged for months at end, their endurance only limited by the physical and mental endurance of their crews.