On the contrary, secure computational infrastructure furthers national security. US happens to have a very large footprint of vulnerable infrastructure as compared to other nations that tightly regulate their Internet. Believe it or not, more secure devices are actually good for the US. There have been several articles and discussions around it and the government has been working closely with the industry for years to improve the security posture.
There's also a news article every few months talking about how the FBI or some other government agency wants to make encryption illegal and how iMessage is a boon to pedophiles all over the world and protects criminals. So, not sure how you can confidently say "On the contrary!"
