The U.S. National Missile Defence project is basically a scaled-down version of the "Star Wars" scheme that was proposed, and discredited, in the Reagan years. The purpose of the project is claimed to be the ability to intercept, in space, a small number of missiles launched against the USA. The missile defence proposal poses a giant conundrum, because the costs, financial and strategic, appear much greater than any benefits to the USA. If, as its proponents say, the system would be capable only of intercepting a few attacking missiles, the scheme offers no defence from an assault by any serious antagonist. The costs, on the other hand, are massive, not only in consuming billions of dollars by itself, but in fuelling a new arms race. All this, while the United States is a signatory of the Outer Space Treaty, which aims at preventing the weaponization of outer space. Russia and China have given sharp warning of their response to any deployed missile defences -- rearmament.
The deployment of hundreds of sophisticated weapons and electronic jamming equipment would make the commercial development of space uneconomical. Many of the weapons could be used offensively against land targets. Lasers capable of destroying ballistic missiles can also destroy the enemy's cities by fire storms. The warning time would be seconds rather than minutes. The result of fire storms could effect the climate as bad or worse than a nuclear warfare.