The US is the largest arms dealer in the world and sells ass tons of equipment to the EU. Ain't nobody going to be buying US arms if they think they could be cut off on a whim. Large parts of the US economy are based on arms production and sales, and a large part of the US's non-arms trade is thanks to the US protecting its trade routes and partners. If the US stops protecting its trade, people will stop preferring trade with the US because it will now be vulnerable and near impossible to secure as a smaller nation because it has to cross the largest oceans in the world.

They’re responsible for honoring their agreements and contracts. How can any European state now trust the F-35s that they’ve purchased or going to purchase? All the trans-Atlantic trust built since 1945. Flushed down the toilet in a few weeks. Trust is difficult to build but easy to destroy.

Because it's been a really good deal for the US. 1. European countries have (for the most part) not had an incentive to build military might, which means they won't be adversaries to the US. 2. This dependency on the US has given the US a lot of soft power in terms of diplomatic pull. In the past, the US could just ask Europe to jump, and Europeans would ask how high. 3. In addition to Europe, it's also kept Russia in check, because it has prevented them from expanding to the west.

Brexit damaged the UK's economy and partnerships. The actions the US keep taking are like that but worse. They are pissing off allies in Europe by doing things like this, they are damaging their own economy and partnerships by threatening and placing tariffs on allies for no real reason.

It was a win win arrangement of sorts. Europe got to spend less on defense. US won a reliable ally that would not challenge them much, and help enforce worldwide US dominance. Basically a near vassal situation.

Brexit was about repealing long-term commitments for short-term gain, and a healthy does of FU to closest partners for domestic publicity. Oh and the short term gains never materialised, it was all costs in the end.

I see this as analogous. US is maybe reaping some short term benefits from flipping on its allies, but burning the bridges it very much relies on.

The US administration agrees with you. It also decided it doesn't want to sell weapons to the Western world anymore, and that it wants to carry the cost of weapons development all itself without relying on exports.

It also wants to forcibly grow competing defense contractors in Europe.

Without much background in the politics, the parallel I see is this:

Group A and Group B build an economic partnership under consensual terms generally favourable to both over a long period of time.

At one point, Group A decides to withdraw due to real or perceived inequality. The timeframe of withdrawal is faster than entering, and is insufficient to unearth the complex network of roots that took generations to plant.

When the trunk is pulled, the pain is felt in vast numbers of small ways that add up. These roots are what contain the vast majority of the surface area after all.

> I don't get why it is a good or logical thing that the US should be responsible for the majority of "Western" defense on our territory.

Read some history (everything geopolitics after the second world war), you should ask yourself why for 76 years that's exactly what the US did (and perhaps why this is the first time that question occurred to you).

It's because the relationship between Europe and the US is not a mutually beneficial one, the US benefited the most from its power and influence over western Europe, and that doesn't just apply to Europe. NATO and the roughly 128 military bases in 58 different countries don't exist because the US somehow likes to subsidize the military spending of these countries for some altruistic purpose, it exists because it strengthens US influence across the world.

That's soft power, and if it fails, it means war (in total 123 military conflicts since WW2). It's a less bloody alternative to make sure the US gets what it wants because its the stronger party in any geopolitical relationship.

That's the logic behind it. The same logic applies to military aid it gives to Egypt and Israel (that Trump continues to give).

The US was never in the European Union, but has always been the leader of NATO and, since WWII, the "Western world". Trump bringing the US out of those positions is a bigger deal than Brexit, because the UK was never a leader in the EU (because of all the internal opposition to it).

> Why is it the US's responsibility to finance and organize the majority of EU's defense?

This is a common talking point, but I think it is totally wrong. The US didn't finance and organize Europe's defense.

They did spend money on their own defense forces which happen to be best positioned in Europe near the best interest as a superpower.

America spent money against their Russian adversary. This money was always well spent as far as I can see it.