The U.K. government has approved China’s plans to build a “mega embassy” in London. After years of delay, Prime Minister Keir Starmer endorsed the project, despite concerns that the embassy would be used for spying. The decision is a bad one from an unpopular and misguided administration, and it is sure to complicate the increasingly fraught relationship between Britain and its foremost ally, the United States.

On Jan. 20, the Starmer government announced that it would allow the Chinese to build the biggest diplomatic facility in Europe, 614,000 square feet in central London. The building’s size reveals China’s ambitions, which, with China’s recent pattern of behavior, are sparking concern.