Hit ‘em now? Or wait?
“Countries That Possess Nuclear Weapon. There are nine such countries that possess atomic weaponry and that are Russia, the United States, France, China, United Kingdom, Pakistan, India, Israel, and North Korea.”
Japan could produce them any time they want to.
They also have mobile ICBMs in a network of tunnels, which we can’t destroy.
Building fixed silos is for greater throw weight missiles so they can really batter us to nothing.
You are suggesting that we should launch an unprovoked, surprise attack that would start a ball rolling down a hill that would damage the US, Japan, and The Philippines; and the utter destruction of Hong Kong, Taiwan, and South Korea?
I don’t think you’ve thought this through.