A small group of fishermen ply the shallow coastal water along Pooneryn in northern Sri Lanka, an impoverished, remote area not far from India’s southern tip. It’s where Gautam Adani — the Indian billionaire who is Asia’s richest man and has vaulted ahead of Jeff Bezos this year — plans to build renewable power plants, thrusting him into the heart of an international political clash.

With Sri Lanka in the throes of its worst economic crisis since its independence from Britain in 1948, India is re-engaging and attempting to tilt the balance in a strategic tussle with China on the island, a pivotal battleground because it lies on key global shipping lanes and plays into New Delhi’s fear of encirclement from its Asian rival.

At the forefront of those efforts is Adani, who is a long-time supporter of Indian Prime Minister Narendra Modi, and has been accused by some Sri Lankan lawmakers of signing opaque port and energy deals closely tied to New Delhi’s interests, something his group has always denied, saying the investments meet Sri Lanka’s needs.