I've been following up on this and sadly I can tell you that the world's nations have failed to enhance their space exploration capabilities in the last 20 years like the US did, so here is whats gonna happen in the next 20 years: The major five or the grand five countries of the world will start the space mining business through their private and public sectors and sell the research, technology and raw materials to other nations and companies for a monetary amount, it might seem selfish but lets face the facts as we are supposed to be science oriented in our decision making process, for example asteroid "ANTEROS" is a metallic based asteroid that is worth around 5.5 Trillion dollars, it will cost more than 3.5 trillion dollars to mine that asteroid, private companies and smaller nations cannot afford to pay that money and they don't have the capabilities for pulling a successful space mining mission. What I'm trying to say here is that I would rather see the US start the race now than wait 30 more years for the freaking world to meet one hundred times and decide how are they gonna do it. On the other hand, Trump's executive order clearly says that anybody can start his own private company and contract for major space exploration missions or even just research new technology and capabilities, which I think is so great that I really am thinking of doing it myself. Another thought: some nations are still imposing regulations and restrictions on who can develop and test fly drones!! now i really am sorry to say it this way but those nations will never go to space, maybe their rich people will, but only as visitors for history have always showed us that science and knowledge can only flourish within the boundaries of a free nation or institution. Conclusion: if the US will wait for the world to agree to come together as one for the benefit of mankind then nothing will ever happen, if they start the race now then everybody will start running pretty soon to catch up and get a share of the cake and eventually the space mining industry will start shaping and come into existence and this is when humans can start benefiting from it.:)

Depending on the type of asteroid M Types (Metallic) are pretty easy to handle and you can simply push it into orbit using boosters and then slow it down gradually using the help of other celestial bodies like the earth and moon, as for C and S Type asteroids, the most promising techniques is called "Queen Bee™ System" and is currently under development by TransAstra Corporation, it depends on optical mining technology to break the asteroid into smaller pieces, pretty interesting approach if you ask me. , here is a link to their videos: Video-1: https://www.youtube.com/watch?v=X5GKz9XLh70 Video-2:https://www.youtube.com/watch?v=y09XY-ekQhM