To be able to stop intercontinental rocket/nuclear attacks, makes the USSF already essential and ultra important. Not only for the protection of the US by anyone, whoever it is to launch a nuclear attack on the US, but also the hundreds of billions of dollars it saves for the development (and knocking out the need) of anti-continental rocket systems. Mining gold, iron, nickel, water and other valuable elements that can be found with the Asteroid Belt, NASA has estimated the mineral wealth of the entire Asteroid Belt could be as much as $700 quintillion (that’s in the good old US dollars)
In the so called mainstream media, almost everything that President Trump is doing and saying, is seen as a joke, nonsense and underestimated. Russia and China clearly disagree with that approach and see it as a serious problem for their possible existence in future. And they are right. With the US (and others) investments in space with many applications like navigation, reconnaissance, weather forecasting, intelligence collection, communications, command and control, precision targeting and much more, the risk of that being destroyed by other countries like China and Russia is too great. Its reliance on satellite-guided munitions has increased with each new conflict in recent years.