Imho not much in life is 100 %. Many shades of many colo(u)rs maybe. Can or should globalisation co-exist with localisation and protectionism ? Well sometimes is my opinion. Which times you may well ask ? Ah now that is a good question.
Yes it's a non-convex optimization problem and solution is somewhere in middle. All market impact is not same. When your trade is large do you not care about market impact? That is one kind of market impact. Political impact is another kind. For Infosys, TCS, Carrier, Ford who have either stopped relocating factories or have decided to move jobs back to USA, political impact is market impact and just like a trader if they don't account for it, they know their losses will be bad. If hiring of vol trader has market impact and corporation didn't account for it, it's not good business. And yes corporations did account for the market impact as you have already seen.
Whatever they are doing, it all boils down to trying to make more money. The moment policies will become so detrimental that they will have to operate at a loss, they will abandon these operations regardless of the social cost. At least that's what sane business would do. If you want to look at the result of extreme protectionism, look at the passenger cars manufactured in Russia or the agriculture in the US. Neither can remain competitive without government subsidies and you'd have to explain to me how is it a good thing for anyone aside from a small group of workers/farmers (and politicians that court their vote).
Just as a matter of interest what are the US prices for :- 250 gram of butter 1 pint of milk 1 brown loaf 1 litre of petrol ( gas ) I will get our prices tomorrow at the supermarket. Brexit may raise prices a bit even though we will no longer be subsidising EU farmers.
That's basically the Scandinavian model. They've got the highest standards of living but there's hindered opportunity to be exceptional like in America.
Potentially moving to a Cosmopolitanism system would be a probable direction. https://en.wikipedia.org/wiki/Cosmopolitanism Cosmopolitanism is a broader concept than world government
This is where Socialism falls flat on its face. Here in the UK Corbyn is going on with 70s and earlier failed policies. They just can't face reality but blame others.
Trump is a great businessman, but he's great not because he's smart. He's a great salesman, probably the best in history. If you think that he's intelligent than you probably an idiot, I am sorry to tell you that, but it's obvious.
Looks like another U turn by Trump as he assures G7 that the US isn't going protectionist. Nobody believes a word he says anyway.
You seem to be attempting to correlate globalization to decline in the wealth of the U.S. middle class. But this correlation is mainly a U.S. effect. Other countries that are also increasingly globalized have seen the wealth and size of their middle class grow tremendously or change little. It seems that while globalization and the decline of the U.S. middle class is correlated, these factors are not related as cause and effect. As a matter of fact, it would be easier to argue that globalization has made the decline of the U.S. middle class less severe than it otherwise would have been.