Steel (or at least the iron in steel) is recyclable.
Iron is magnetic. Most landfills pass our waste stream under electromagnets and we capture and reclaim a huge portion of waste iron.
Currently the Trump Administration is seeking to impose tariffs and restrictions on imported steel claiming that that steel is a strategic commodity that we need to protect for national security.
I say that, because iron is so easily recycled, it is actually in our nation's strategic interest to import steel.
All of the steel things that we import help our nation build up a strategic reserve.
If there is an international crisis that suddenly requires a great deal of steel, we can easily recycle the huge steel reserve that we imported.
Let's say we had a conflict with China. All of the steel that China exported in times of peace is steel they no longer have and that we have in reserve.
As for iron and coal reserves in the ground, we are in a better strategic position if we leave our resources in the ground and let China overdevelop their reserves.
If we have a national crisis that suddenly requires a great deal of steel, our nation can easily ramp up steel and coal production. The huge amount of recyclable metal that we have in our nation plus the ability to ramp up undeveloped reserves puts us in a better position than a false market where we use tariffs to block steel imports and consume our natural iron reserves in times of peace.