Chile for decades finessed the geopolitical rivalry between China, its top trading partner, and the U.S., its leading foreign investor.

Those days seem to be over.

Just days ahead of a summit of Latin American leaders in Miami and two weeks before a right-wing government takes over in Santiago, the U.S. imposed visa restrictions on three Chilean officials tied to an undersea digital cable project proposed by Chinese firms, alleging a security threat. The rare move sent a warning to the region that it must now choose sides as President Donald Trump strives to reassert dominion over the Americas.