Yes: one of the US national security launch vehicles, Atlas V, uses imported Russian main engines. US defense access to space was dependent on Russia for much of the 21st century (after the retirement of the Titan rockets).

https://en.wikipedia.org/wiki/RD-180

https://en.wikipedia.org/wiki/National_Security_Space_Launch...

https://news.ycombinator.com/item?id=30542226 ("Russia halts deliveries of rocket engines to the U.S. (reuters.com)")

(It's not a national security payload, but the Starliner ISS astronauts also went up on this Russian engine).