Foreign countries using Google, Microsoft, or Apple, would be suicidal not to change platforms. Right now, the U.S. has incredible leverage: it can turn off their government servers, delete their data, and is certainly spying on them right now.
The only reasonable move is some kind of self-hosted setup, at least for a large chunk of critical infrastructure, with some cloud options for backups, maybe, who knows, if the country is too small or centralized.