MUKESH D. AMBANI during the 鈥淧reparing for the Fourth Industrial Revolution鈥 Session at the World Economic Forum in Davos on Jan. 17, 2017. 鈥 WORLD ECONOMIC FORUM/VALERIANO DI DOMENICO/FLICKER

By Andy Mukherjee

FROM OTTAWA to Beijing, President Donald Trump鈥檚 trade war has made many enemies. But it has also won America some allies. Asia鈥檚 richest tycoon is preparing to welcome US cargo originally meant for China but . The ship Mukesh Ambani is waiting for is laden with ethane.

This colorless, odorless component of natural gas is shipped in liquefied form in special carriers such as , which is currently on its way from the US Gulf Coast to billionaire Ambani鈥檚 terminal in Dahej, Gujarat, on India鈥檚 western seaboard. There, his flagship Reliance Industries Ltd. has an ethane cracker to produce ethylene, a of plastic products.

The unit, completed in 2017, made Reliance 鈥渢he first company to globally conceptualize large-scale imports of ethane from North America as feedstock,鈥 it boasted in a back then. Eight years later, that foresight may come in handy to trade negotiators in New Delhi. 鈥淪top obsessing over your $43 billion trade deficit with us,鈥 they might like to tell their counterparts in Washington, as both sides try to close a deal ahead of the July 9 US deadline for 26% reciprocal tariffs. 鈥淲e鈥檙e going to buy your gas.鈥

The 68-year-old petrochemicals czar bet on North American ethane more than a decade ago. His father Dhirubhai Ambani, the founder of the empire, was the original And although the son has ventured into new areas and added $57 billon in retail and digital services, the annual revenue from the legacy oils-to-chemicals business is still bigger at $74 billion.

Historically, Reliance and other refiners have cracked naphtha 鈥 obtained by distilling crude oil 鈥 to make ethylene. The conversion efficiency is low at around 30%, compared with 80% for ethane. But since crude oil had to be imported anyway to produce motor spirits, it made sense to use it for making polyester and other polymers as well. Ethane, which on an energy-equivalent basis is half as expensive as naphtha, hasn鈥檛 been popular until now. In fact, Qatar didn鈥檛 even bother to separate it from the natural gas it supplied to India. But even that is changing. Under a new agreement with India鈥檚 Oil & Natural Gas Corp. (ONGC), . If the buyer wants ethane, it will have to pay for it.

ONGC recently entered into a deal with Mitsui OSK Lines Ltd., which will build, own and operate two for the state-owned firm to import ethane. Here, too, Ambani wrote the template. Reliance co-owns a fleet of . It now wants to lay a pipeline to bring ethane from the terminal to another of its processing units in Gujarat. New capacities for ethane cracking are coming up, too, including by GAIL India Ltd., a public-sector firm like ONGC.

It isn鈥檛 clear if this entanglement with North American feedstock will expand indefinitely. Just how much more ethane could Reliance and others handle? After all, it鈥檚 still an oil-centric economy they serve. But if the dependence grows, it could profoundly alter India鈥檚 fuel economics. For one thing, Indian state-owned refiners may become unprofitable dumping grounds for Middle Eastern crude. Any for the naphtha they churn out alongside transport fuels won鈥檛 compensate for the loss of its central role in making everything from polyester and detergents to fertilizers, cosmetics, and pharmaceuticals.

Oil is on extra time in India. A third of the vehicles sold last year by the nation鈥檚 largest carmaker run on compressed natural gas. To manage pollution, and reduce dependence on imported fossil fuels, New Delhi has mandated the addition of . Mass adoption of electric vehicles will further cut into gasoline demand. Even then, a government-controlled firm is setting up a in the southern state of Andhra Pradesh. I suspect the reason the project is going ahead is because the state, eager to attract capital and create jobs, is offering lavish subsidies. Otherwise, the investment case is weak.

Meanwhile, Ambani plans to to its fleet. Now that Trump has fallen out with Elon Musk, the White House may have room for a new centi-billionaire guest. Both parties may gain from a closer friendship. While the trade war with China is on pause, the fate of . Although India can鈥檛 match the much larger Chinese appetite for cracking ethane, it can certainly absorb some of the oversupply. Trump will get to brag about how his trade policies are making America great again 鈥 and his sons may get some tips on how to run their . Ambani will fight off the by shifting to a cheaper feedstock.

The tycoon runs India鈥檚 biggest telecommunications and retail networks, but it鈥檚 only now that his family has started climbing up on the list of global celebrities. First came the glitzy, five-month-long, celebration last year of the youngest of the three Ambani children, the heir apparent of Reliance鈥檚 energy business. Ivanka Trump and Jared Kushner were . Then Trump met Ambani and his wife, Nita, at his . This fall, Nita Ambani will take over New York鈥檚 Lincoln Center for a weekend.

Making a mark as a big buyer of American ethane may not draw the attention of Vanity Fair. But the White House will surely take note.

BLOOMBERG OPINION