HONG KONG (AP) — The Chinese government’s move to open an antitrust probe into Google is the latest development in a long and tangled relationship that goes back to the early 2000s.

China's antitrust investigation into Google, which does not offer most of its consumer-facing services including search and email in the country, seems to make little sense on the surface, but analysts said the move could be seen as a warning shot to the US and a threat to the Android operating system.

China hit back at the U.S. with tariffs of its own. Beijing also said it was starting an antitrust probe into Alphabet’s Google.