Because the same issues that apply in the US military apply elsewhere, and because the US is seen as a leader on many of these things, once you start doing these things, it becomes much harder to resist it elsewhere. It also seems to work to some extent in the opposite direction - what happens in other countries is often used to try and put pressure on American institutions.
Nothing happens in isolation.
Do you hear anyone, on this forum, talking about aussie training? All things happen now. What we do, is not your purview. Ever.