New Delhi, Sept. 17 -- President Donald Trump never got Mexico to pay for his border wall, but he's having a surprising amount of success getting Japan to pay for America's artificial-intelligence data center buildout.

Japan has already approved government loans for three gargantuan natural-gas plants in Ohio, Texas, and Pennsylvania. If they opened today, they'd be the three largest gas plants in American history, powerful enough to provide all the electricity needed by both New York City and Los Angeles on an average day. All three are expected to power AI data center complexes.

The projects and the financing schemes behind them are unlike anything seen before in the U.S. Japan has agreed to commit as much as $550 billion on American ...