The United States has about 500 Minuteman intercontinental ballistic missiles with nuclear warheads (it also has land based Peacekeeper Missiles (about 50), submarine based Trident nuclear missiles, and aircraft based nuclear weapons). They aren't in the news as often as they were in the 1980s when the United States and the Soviet Union were in a cold war standoff. But, they are still there and they still work. A couple of weeks ago, an unarmed one was launched from North Dakota to a Pacific Ocean target as a test. It crossed the 4,000 miles in 30 minutes (more than ten times the speed of sound at sea level). Equally important, the U.S. is preparing to take a much more aggressive stance regarding when it is prepared to use those missiles pre-emptively.
A single Minuteman missile can annihilate an entire metropolitan area. But, while the U.S. has the power to rain down massive destruction anywhere in the world, the military value of destroying whole metropolitan areas full of mostly innocent people is questionable. The U.S. has all the sledgehammers it needs, but most wars, which are politics by other means, call for jeweler's screwdrivers, not sledgehammers.