Direct military action isn't the only recourse. It would be a pretty dangerous course of action. There are a lot of Chinese investments in the UK that could be

Direct military action isn't the only recourse. It would be a pretty dangerous course of action. There are a lot of Chinese investments in the UK that could be seized, as well as information warfare, travel restrictions, trade restrictions and Cold War style proxy wars. Also things like giving HK BBO holders a route to British citizenship, which has high levels of support across the political spectrum and could probably be expanded further.