We're seeing this very clearly in the automotive industry, with "US-made" American brands having large numbers of foreign-made components (complicating the tariff picture), often more than Japanese brands that are made in US factories. Changing the global supply chain back to a less-distributed model would take years and years, and isn't necessarily a desirable outcome anyway.

I think the critical point in this is trying to ensure that foreign elements of the global supply chain that we rely on are situated in nations with whom we have no geopolitical reason to be in conflict with. The obvious example of this not being the case is our huge reliance on China, a nation with which the US stands a not-unreasonable chance of finding itself in a shooting war with. Ideally (from a geopolitical standpoint) we'd self-source critical supply chain elements that we currently get from China. But that "ideal" situation is for all practical financial purposes unattainable. We have to find alternate sources in nations that aren't potentially going to be chucking hypersonic missiles at our aircraft carriers...