Commentary Welcome to the newest frontier in the struggle between the United States and China for geopolitical dominance: the struggle for control of the strategic commodity of the future, data. The latest casualty in this battle is Didi, the Chinese Uber, UBER +2.8 percent, lookalike with 377 million annual active users and 13 million annual active drivers. Its agony began soon after Didi shares started trading publicly in New York, following a $4.4 billion initial public offering. Little more than two weeks later Chinese authorities sent state-security and police officials into Didi’s offices. The official story was that authorities worried the data Didi users share with the company, including cellphone numbers which in China are linked to their real names and identifications, are insufficiently protected, especially from the prying eyes of Didi’s foreign investors. A related crackdown on a range of Chinese companies doing business in the United States has sent Chinese tech stocks reeling worldwide. Beijing’s …