Lots of things are threats, including long-range stealth bombers, of which the USA already fields 19, and is manufacturing more. Attack submarines are a threat as well, because they can destroy SSBNs, which are the only credible second-strike credibility.
Lots of things are threats, including long-range stealth bombers, of which the USA already fields 19, and is manufacturing more. Attack submarines are a threat as well, because they can destroy SSBNs, which are the only credible second-strike credibility.