Abstract: India's defence relationship with the United States began from almost nothing. Non-alignment and India's Cold War-era closeness to the Soviet Union kept the two countries at arm's length through most of the twentieth century, and meaningful institutional cooperation only began with the 2002 General Security of Military Information Agreement. From there the relationship was built up in step by step: in 2016, 2018 and 2020 Logistics Exchange Memorandum of Agreement, Communications Compatibility and Security Agreement, and Basic Exchange and Cooperation Agreement were signed respectively; the 2016 Major Defense Partner designation and the 2018 2+2 Ministerial Dialogue gave the relationship its own diplomatic and institutional architecture; and the 2023 technology initiatives, the 2025 COMPACT framework, and the October 2025 ten-year defence framework moved cooperation from access toward genuine co-production between both countries. By any institutional measure, the United States is now one of India's most significant defence partners. However, Russia remains the more reliable defence partner in practical terms. Russia still supplies India with more arms than any other country, and decades of familiarity with Indian platforms, combined with easy licensing conditions that govern U.S. transfers, give it an operational reliability that the newer U.S. relationship has not yet matched, even as recent wartime delivery delays have tested that reliability. This paper traces both halves of that story: a rapidly deepening institutional relationship with the U.S. and a still unmatched level of practical defence cooperation with Russia.