New Delhi, Sept. 17 -- Prime Minister Narendra Modi's 76th birthday on Thursday unfolded not merely as a domestic political occasion but as a distinctly international moment, with world leaders, ambassadors and foreign diplomatic missions sending messages that underscored the breadth of India's engagement with the world and the personal diplomatic equations built up by the Prime Minister over more than a decade at the helm of the country.

From Moscow to Tokyo, Canberra to Bratislava, greetings for Modi carried references to strategic partnerships, economic cooperation, technology, people-to-people ties and the expanding diplomatic architecture around an India that is seeking a larger role on the global stage.

Russian President Vladimir Pu...