Well, there's a lot of nuance here so I'll speak quite generally in that the United States could certainly afford to wait 20 years to see a return on investment (we do this with many, many programs and policies even today - NASA for example, food stamps, education) and I'd also argue that a country to the extent possible would tend toward valuing the ability to produce goods in the event that the supply lines of goods being imported is shut off.
Further, you could make investments now that exceed current capacities and capabilities today with an eye to the future.
I want to clarify that I’m 100% in favor of such a policy, in principle. It’s the implementation that’s hard.
Actually the US does a lot of good manufacturing in some fields, like arms. But in other fields, well-intentioned protectionist policies like have backfired. For instance, rather than subsidizing US shipyards, the Jones Act protects them from foreign competition which has led them to significant decline over the past century.
US policy to rebuild or improve US industry has a very mixed history in terms of results. It probably doesn’t help that a lot of these efforts are focused on bailing out the same old manufacturers over and over again to save jobs in battleground states.
Further, you could make investments now that exceed current capacities and capabilities today with an eye to the future.