It’s true that NASA are the premier national space agency, but this hasn’t always been the case: until we actually started sending astronauts to the moon, Russia was kicking our butts in the space race. And even into the modern era, other national agencies have done and continue to do awesome things. The ISS is a true collaboration, as is Cassini. The U.S. certainly does not have a monopoly on space exploration.
And, as I laid out above,