Russia, armed with nuclear weapons has achieved a supremacy over Germany that it will never relinquish. That is the bottom line reality of nuclear weapons in Europe.
Similarly, the Chinese know that as long as they have the ability to hit the United States with nuclear weapons, they will not be invaded because they fail to meet the democratic standards of the West, or that they treat Tibetans in a way the blue-eyed people find objectionable.
This blog argues that because nuclear weapons fundamentally reflect engineering talent, which is to say IQ, nuclear weapons help the poorer backward country that can develop exceptional engineers: See North Korea. Sooner or later the American establishment will either accept this, or will run the risk of living under platforms for nuclear weapons in space.
The fact that Russia and China may respond to an American defensive system in space by putting an offensive system in space, is as dangerous a possibility as America has ever faced.