Every major power wants backdoors in these systems. Asking the producers to put in a back door is just one mechanism. They are also putting plants/spies in these companies as employees, bribing people, etc. And they have practically an infinite budget. It's not a matter of if but when. It's a reasonable expectation that any sufficiently large system that has been around for long periods of time has been compromised by spooks. If they aren't compromised, then every spy agency on the planet is shockingly incompetent.