Comparing this to libel/slander is just absurd. It’s not a slightly different category, it’s such a massive difference that Europe has essentially outlawed aspects of political speech, which is the most important aspect of freedom of speech to begin with.
Here's my question: under your definition, how could "thoughtcrime" possibly be detected, let alone punished?
This is one of the central themes of 1984, that Ingsoc ("the Party") tries to control not just the speech and actions of their subjects, but their very thoughts. Literally: in 1984, having thoughts that goes against the party is illegal. That is why it's called "thoughtcrime", because it's the thought itself, even if it goes totally unexpressed in any way. Such crimes are punished by the "Thought police", who quite literally police thoughts. When a dangerous thought presents itself, you're supposed to use "crimestop", a technique for ridding yourself of that thought. Here's a quote from 1984:
> The mind should develop a blind spot whenever a dangerous thought presented itself. The process should be automatic, instinctive. Crimestop, they called it in Newspeak.
Oh, and yes: Newspeak! The language developed by the party with restricted vocabularies and grammar so that some thoughts will be literally unthinkable.
I took that quote from the wikipedia page on "thoughtcrime", which helpfully begins like this:
> A thoughtcrime is an Orwellian neologism used to describe an illegal thought. The term was popularized in the dystopian novel Nineteen Eighty-Four by George Orwell, first published in 1949, wherein thoughtcrime is the criminal act of holding unspoken beliefs or doubts that oppose or question Ingsoc, the ruling party. In the book, the government attempts to control not only the speech and actions, but also the thoughts of its subjects.
Feel free to look in any other dictionary or reference work, they will all say the same thing, some variation on "a thought that is illegal". I could go on with many more examples of how 1984 talks about thoughts (you should google "doublethink"! or maybe just read the book), but you get my point.
Your reaction, "how could 'thoughtcrime' possibly be detected, let alone punished?" is what the book is about. Every reader of 1984 reacts that way in the beginning, and the book is an exploration about what that very concept means, and what the implications are.
Look, the argument you are making is something like "European hate speech laws are an unacceptable abridgment of free speech and democratic rights". Which is a fine argument to make: I personally don't think so, but reasonable people can disagree on it and discuss it. What it is not is "thoughtcrime". It's just not what the term means.
I am not making any argument about European hate speech laws whatsoever. My issue is solely with the pedantic definition of the word "thoughtcrime" that is at odds with how it's actually used.
You seem to be under some mistaken impression that you can say whatever you want whenever you want in the United States. You can't. There are many categories of speech that are banned in the US as well: if I think to myself "Tom Smith is a liar and a drunkard and he's cheating on his wife", that's perfectly fine, but if I communicate that to a large group of people in order to stain his reputation, that's illegal.
See the difference? In neither the US nor the EU is thinking things illegal, but in both countries, expressing stuff can possibly be illegal. It's true that the US and the EU has slightly different categories of banned speech, but that's a difference in degree, not in kind. but neither region has anything close to "thoughtcrime". You have a poor understanding of these issues if you think that is the case.