If that were to happen, you'd have steel to mine in reserve. But that hasn't. So why rush? If Trump is so bound and determined to make America an island in the clouds, dependant upon no one else, why not develop the tech first, set up the infrastructure, and then pull the plug? Despite all the hysteria, you guys are in a great spot, and have been for years. Sure there are trade deficits with poorer countries -- you guys can afford more than their citizens can! In the meantime, you are getting goods much cheaper than if they were all made in the U.S.A., which you've already paid for in the form of lost jobs that aren't coming back no matter what, use that advantage to build a system where you can be self sufficient without bankrupting yourselves, and in turn the rest of the world (like what nearly happened in 2008). And, if you guys want to be Christian about it, share that tech so other countries can do the same. Or don't, the rest of the world seems to be working towards getting along better at the global level anyway.
Instead, you'll have the entire world entering into a trade war with you. There is no economist out there right now that will say that's a good thing, unless they are getting a nice big payout to do so. And the response from the world seems to indicate that they aren't simply going to sit back and pay. I understand your concern, but you're advocating for the shooting of your own foot.