This is all very fuzzy. Are you saying that China and India, which have big domestic markets but are historically very protectionist, are suddenly going to reverse course, open up their domestic markets, and make their domestic companies compete with international firms? Because if you understand the domestic political situation in those countries you will know that this absolutely is not going to happen.
The thing a lot of these criticisms of the tariffs always come back to is "everyone's now going to hate the US and sell to someone else instead." But this analysis ignores the fact that the US before April 2 was radically less protective of its domestic markets than pretty much all the other major economic powers. This is a discussion I was having with people long before Trump was elected and you can always tell who has actually looked at the trade relationships of these major economies over the years and who hasn't. China for example is notorious for essentially doing what Trump is doing now, whenever it becomes a political hot button internally, they just cut off trade with some country or other. Every country is shopping around for new trade partners all the time, regardless of what the latest POTUS is up to, and there just is no magic untapped market that's going to materialize and fill the gap.
A lot of countries are simply going to lose their #1 or #2 export market with no replacement if they don't deal. Sure we can make an argument that given 20 years something magic will happen and BRICS will all become free market liberals and sing kumbaya to each other. But this year, countries will deal.
What is not fuzzy is the depth of disappointment and distrust the US has gained across the Atlantic Ocean. Which has long-term economical, cultural and political consequences.
Dealing with a friend is certainly different than dealing with a foe. The USA look nothing like a friend anymore. How do they expect this to turn out in the next 10 years?