Sound like some political spin on your part, or just head in the sand.

It's how trade starts, small friction reductions. And now that trade is happening anyways, and there are newer better ports, it becomes easier to do more trade. And trade grows. With better new trade routes/infrastructure they aren't just selling the Europe, they are taking more and more market around the world.

For the USA that 'tiny' to you 3% is going to wreck a lot of red, agricultural states economies. And they then become drags on other parts of the American economy, and instead of chasing opportunities we're propping things up. Less trade impacts all trade, because suddenly things get tighter for Mississippi shipping. Train lines. There's less synergy, more expense carried by the remaining industry. Less money for maintenance/reinvestment in bulk transportation. Less money going into John Deere and all those agg adjacent companies. Less money for our petrochemical companies (fertilizer) means less reinvestment for them/worse health, higher risk from foreign competition.

For example 60% of farm exports travel over rivers, and 20% of coal. So coal shipping prices might get impacted. Maybe coal shipping efficiency as river shipping lanes lose 60% of their business there is less put back into maintaining them. Coal isn't in a position to absorb much shock, it's doing really bad already.

Chemicals are 9% of US exports. More ag trade makes it profitable for companies in these other countries to start setting up their own petrochemical factories/industries that will then compete with us as well.

Edit: You missed my entire point. But yes, the US is winning by shrinking our export market and needlessly building up competitors. Everyone envies shrinking markets. You got me.

Not 3%; 7% of 3%: 0.2%. And, even less than that, because we're not talking about 100% of US agricultural export to the EU disappearing. Nor are we talking about anything happening on any immediate timeline. But sure, there's political spin. Your viewpoints are also spun around politically. That's every viewpoint; there is no such thing as objectivity when it comes to systems this complex.

This is a good thing for the EU; more diversity in their import partners is a good thing. This is a bad thing for the EU; their farmers are about to see prices for their goods drop. This is a good thing for the US; less international demand for their products means US customers will see more stable prices. This is a bad thing for the US; because of everything you said. How it shakes out is a story for the history books; but the game that's being played right now is far bigger than you realize, and more important.