As the United States marks the 250th anniversary of its independence on July 4, 2026, one of the most remarkable stories of its modern history is the transformation of its relationship with India. Once divided by Cold War politics, nuclear sanctions and deep strategic mistrust, New Delhi and Washington have evolved into close partners in defence, technology, trade and the Indo-Pacific.The contrast is striking. In 1971, during the India-Pakistan war, President Richard Nixon sent a US naval task force into the Bay of Bengal in a move widely seen as backing Pakistan. More than five decades later, India and the United States are negotiating one of their most ambitious bilateral trade agreements, highlighting how dramatically ties between the world’s two largest democracies have changed.Early diplomacy and the era of non-alignmentSoon after India gained independence, Prime Minister Jawaharlal Nehru visited the United States in October 1949 and met President Harry S. Truman. The visit came before India formally emerged as one of the principal architects of the Non-Aligned Movement, which sought to avoid alignment with either the United States or the Soviet Union during the Cold War.The differing strategic outlooks shaped bilateral ties for decades. Political scientist Dennis Kux later described India and the United States as “estranged democracies” in his influential book of the same name, reflecting the distance that characterised the relationship despite both being democratic nations.In December 1959, President Dwight D. Eisenhower became the first sitting US president to visit India, addressing Parliament and meeting President Rajendra Prasad and Prime Minister Nehru.Relations deteriorated in August 1971 when India signed the Indo-Soviet Treaty of Peace, Friendship and Cooperation with the Soviet Union, a move viewed in Washington as a departure from New Delhi’s policy of non-alignment. Months later, during the Bangladesh Liberation War, President Richard Nixon ordered the USS Enterprise-led Task Force 74 into the Bay of Bengal in what India viewed as a clear signal of US support for Pakistan.Nuclear tests and years of sanctionsAnother major setback came in 1974 when India conducted its first nuclear test at Pokhran, describing it as a “peaceful nuclear explosion.” Codenamed Smiling Buddha, the test made India the first country outside the five permanent members of the UN Security Council to demonstrate nuclear capability, but it also triggered restrictions on international nuclear cooperation with New Delhi, according to the BBC.Story continues below this adRelations worsened again in 1998 after India conducted the Pokhran-II nuclear tests. The United States imposed sanctions under its domestic non-proliferation laws and recalled Ambassador Richard F. Celeste in protest, according to the US State Department.Kargil conflict and diplomatic thawThe relationship began improving after the 1999 Kargil conflict, during which the United States pressured Pakistan to withdraw its forces from Indian territory.President Bill Clinton’s landmark visit to India in 2000 further accelerated the thaw, while President George W. Bush lifted the remaining sanctions in September 2001, according to the Council on Foreign Relations.The civil nuclear agreement transformed tiesThe defining breakthrough came between 2005 and 2008 under Prime Minister Manmohan Singh and President George W. Bush with the landmark India-US Civil Nuclear Agreement.Story continues below this adThe deal effectively ended India’s decades-long nuclear isolation despite New Delhi remaining outside the Nuclear Non-Proliferation Treaty (NPT). Under the agreement, India separated its civilian and military nuclear facilities and placed civilian reactors under International Atomic Energy Agency (IAEA) safeguards. In return, the United States agreed to facilitate civilian nuclear cooperation with India. The US Congress approved the agreement in October 2008.The nuclear deal is widely regarded as the turning point that fundamentally reshaped India-US relations.Defence and strategic cooperation deepenDuring Barack Obama’s presidency, bilateral ties expanded beyond nuclear cooperation into defence and strategic engagement. The two countries launched the first India-US Strategic Dialogue in 2010, while defence cooperation steadily increased.The Logistics Exchange Memorandum of Agreement (LEMOA), signed in 2016, allowed both militaries to access each other’s bases for logistics support, significantly strengthening defence interoperability.Story continues below this adTechnology, Indo-Pacific and the China factorThe partnership expanded further under Prime Minister Narendra Modi and successive US administrations led by Donald Trump, Joe Biden and Trump again.Growing concerns over China’s expanding influence in the Indo-Pacific pushed India and the United States closer together. The revival of the Quadrilateral Security Dialogue (Quad) in 2017 brought together India, the United States, Japan and Australia to promote a free and open Indo-Pacific.The two countries also deepened cooperation in emerging technologies through the Initiative on Critical and Emerging Technology (iCET), focusing on semiconductors, artificial intelligence, quantum computing, telecommunications and defence innovation.Trade tensions give way to a fresh resetDespite closer strategic ties, trade remained a recurring source of friction.Story continues below this adRelations came under strain after the Trump administration imposed steep tariffs on Indian exports in 2025, partly citing India’s continued purchases of Russian oil.However, both sides announced an interim trade arrangement in February 2026 that reduced US tariffs on Indian exports from 50 per cent to 18 per cent. The agreement also committed the United States to purchasing about $500 billion worth of Indian goods and critical materials over five years, with a focus on semiconductors, agriculture and critical minerals, according to the Associated Press.Recent talks in New Delhi involving US Secretary of State Marco Rubio have further advanced negotiations toward a comprehensive bilateral trade agreement expected to deepen economic cooperation.From estranged democracies to strategic partnersThe proposed trade agreement represents the latest milestone in a relationship that has undergone a remarkable transformation over the past seven decades.Story continues below this adFrom Cold War suspicion and nuclear sanctions to cooperation in defence, technology, trade and the Indo-Pacific, India and the United States have steadily built one of the world’s most consequential strategic partnerships. As Washington approaches the 250th anniversary of its independence, the evolution of India-US ties stands as one of the defining geopolitical shifts of the post-Cold War era