Rather than strengthening the position of US companies, I think this might weaken them in the long run. Who wants to depend on US products if they are liable to be taken away at a moment's notice?
Pretty much every Western country will, because they depend on the US. If the empire goes, the provinces follow.
It's another thing for Russia, but they are already well aware. India? Probably still in a role where US-dependence does more good than harm. For Africa, it doesn't matter as much, and South America likely remembers that it's unwise to stray too far from the northern neighbor's wishes.
Your optimism regarding the future of the US empire is belied by long term trends, not only the phenomenal rise of the Chinese economy: The EU has since it's inception had its eyes set on greater independence from the US. Case in point, Macron and Merkel are calling for a European army now, but not because of Trump, it's been the plan all along.
Trumps current heavy-handedness in international relationships is instead a direct response to this disintegration of the empire, and it's just hastening the demise. The worrisome part is how the US (and all its hurrahh-boys) are signalling that they will not accept this turn of events peacefully.
I'm not optimistic about the long term future of that model, I just don't see any emancipation of the EU. Of course, Trump is not at all what Merkel, Macron, Juncker etc want, but he's also not at all part of the 20th century US empire.
What China or Russia do is this: key industries must be domestic. The EU countries never did this, they've accepted the US as the provider for information discovery (search), information transmission (news) and communication, granting them enormous powers. Merkel's own BND (certainly not without her knowledge, it's closely lead by the Bundeskanzleramt) cooperated with the NSA to provide access to virtually all German internet traffic so the NSA could spy on German citizens wholesale.
Good luck with that EU army. If the state of Germany's Bundeswehr is any indicator, we'll be lucky if the EU army has a functioning bicycle in 2040.
