The U.S. pledges to protect its Pacific allies from nuclear attack by providing a “nuclear umbrella.” So far it’s worked. The umbrella keeps a lid on proliferation. And countries like Japan build Nissans instead of Nukes.
Folding the Nuclear Umbrella
But if the only country to know what a nuclear hit feels like wanted to go it alone, it could. Walter Russell Mead speculated in the WSJ that Japan might be able to build the bomb in a matter of months. But since it can’t be dropped from a Nissan, delivery could be problematic.
Still, shooting missiles over Japan might be a good way to get things started.