Right. But there is an apparent balance at the moment where because no government has demanded and received back doors, no country mandates it. It's a precarious spot to be sure. But it would be bad for the US to step off the line first.
It's only a matter of time before China feels they can do it. They will, if they haven't yet. Not defending U.S. politicos and bureaucrats who also want it. Just saying that the U.S. asking or not asking for backdoors will soon make no difference.
Perhaps but at that point the US (or whoever) can counter with their own rules/laws. Might lead to manufacturing balkanization but I'd prefer the US not the one to step over the line first in the same way I'd prefer the US not be the first to use nukes (although I guess that's a bit hyperbolic).