Backdoors have been revealed a few times in US products, but US companies have learned their lesson and appear to be pushing back. 9/11 is almost a decade in the past and the Snowden revelations embarrassed several companies. Things like warrant canaries are pretty common and companies like Apple have been publicly fighting government attempts to access Apple devices in court.
One thing the US has going for it is that unlike some countries, is that companies are more scared of their customers than the government.
One thing the US has going for it is that unlike some countries, is that companies are more scared of their customers than the government.