Hi, it says, "Under the terms of the Operating Agreement, we may terminate your account at any time, with or without cause. This decision is final and not subject to appeal."

https://www.heidoc.net/joomla/amazon-global/44-heidoc-net-vs-amazon-com-part-3-closure-of-the-affiliate-accounts

Doesn't this mean that they can do what they want under the terms of service?

Correct. They are allowed to do anything. The affiliate is allowed to do nothing. That's called "substantively unconscionable" in legal lang, and unfair in normal language.

In the EU, they have a similar clause in the terms, but in fact it's no longer valid. EU affiliates may be terminated only when they violate the terms.

I'm a lot more annoyed by their accusations of fraud and conspiracy, while they in turn submitted various false statements to the tribunal.