asteroid-posting as geopolitical analysis, a tale as old as 2:47am

The USA was the only country with nukes until 49, that power difference will not be matched until someone builds something as powerful compared to nukes as nukes were to conventional bombing, and has a monopoly on it. This won't happen because you could hypothetically drop an asteroid and kill everything on earth currently available tech, so planet killing weapons won't lead to another time similar to a nuclear monopoly.