The writer is a lecturer in south Asian studies at Yale University.

In February, Indian Prime Minister Narendra Modi stood beside US President Donald Trump at the White House, projecting optimism as they pledged to lift bilateral trade to $500bn by 2030 and hinted at a new comprehensive trade agreement. In a display of bonhomie emblematic of deepening strategic co-operation, Modi invited the US president to India for the planned Quad leaders’ summit later this year. Echoing Trump’s “Make America Great Again” slogan, Modi declared he was working to “Make India Great Again”, adding that “Maga plus Miga becomes a mega partnership for prosperity.”

Within just a few months, this mega-partnership has given way to mutual recriminations and punitive action. Trump announced tariffs of 25 per cent on Indian imports, accusing New Delhi of erecting “strenuous and obnoxious” trade barriers, then promptly doubled them to a draconian 50 per cent with threats of further increases. The reason: India’s continued purchases of Russian oil, which Washington contends are undermining its sanctions regime on Moscow. Trump has ruled out further negotiations until these disputes are resolved.