This action was a blatant violation of the sovereignty of the nation of Argentina. Yet I hold that it was entirely ethically correct and proper.

You skip all the interesting work right here.

If this is supposed to be a defiance of the new censorship policy by showing that it stifles interesting and important debate, do your best to provoke discussion that's actually interesting.

If you want to discuss the censorship policy, discuss the censorship policy. If you want to discuss this issue, discuss this issue. Don't do the one by pretending to do the other - that's a type of dishonesty which wastes the time of those who thought that you might be interested in the actual issue this topic pretends to be about. Therefore downvoted.

Explanation: This is not actually a post about ethics, it is a post about censorship / moderation. Thus explaining, but not excusing, some of its flaws. And also explaining the downvote brigade.

This post doesn't really say anything interesting about retributive justice at all. It sounds like what's actually bugging you is the question of national "sovereignty". Plus, you Godwined yourself. Between these things, you give a pretty bad impression. Perhaps if you reposted it with a less flamebaity example and a title like "Is there any ethical reason to respect national sovereignty?" or something you might fare better.

'Ethicality' pings my "this is not a word" reflex even though it actually is a word. Does the current title mean something much different than "On the ethics of retributive justice"?

An important difference between Eichmann and Kissinger is that the former was directly responsible for the Holocaust, whereas the later at best acquiesced to the invasion as a mater of political expediency. Think about it this way, do you think the same logic should apply to Roosevelt for his acquiescence to America's then ally Stalin's takeover of Eastern Europe?

You shouldn't expect unique answer to complex ethical questions involving politics. But note that Kissinger was more indirectly responsible for the invasion of East Timor than Eichmann was responsible for the Holocaust. Punishing people who didn't prevent crimes committed by others is rare and restricted to situations where the punished person can be assumed to know for sure about the imminent crime and has relatively easy way to prevent it. Which is almost never true in politics.

(As a tactical note, linking to a Youtube video to support the notion that a well-known politician is a war criminal is probably not so good idea here.)

On a semi-related note: are there any districts in the United States that still allow private prosecution?

A political figure was a high-ranking government official and involved with causing a politically charged, negatively-viewed event. This figure was not immediately punished for their cimes. Later, a group violated several heuristics most humans hold about concepts like fairness and justice, and punished this person for their crimes.

This act both violated some norms about fairness, and satisfied other norms on fairness. I hold a polarising view about the relative worth of the violations and satisfactions.

Later, another political figure was a high-ranking government official and involved with causing a politically charged, negatively-viewed event. This figure was not immediately punished for their crimes. If, hypothetically, a group violated the same set of heuristics most humans hold about fairness and justice, and punished this person for their crimes, would you hold the same polarising view on this matter as the view I held on the previous matter?

Note: On LessWrong, we avoid politics where we can. This is your post, de-politicised.

It is done because I feel that much of the planned impact of this post rests on challenging implicit assumption of political leaning: Holocaust bad, America good. You should at least be made aware that most LessWrongers are not subject to this assumption.

(Much) more generally: examine where your question marks are. If they follow facts, this post fits in Discussion. If they precede convincing logical and rational(1) arguments for the questioned positions, this post belongs in Main. If they follow descriptive questions (i.e. you are genuinely curious about the distribution of beliefs in the LessWrong community) it belongs in Discussion with a prominent link to a survey. If --- as in your case, it does --- follow a prescriptive question (would you hold the same polarising view as me?), then it does not belong on LessWrong.

This concludes the exhaustive explanation of why you were downvoted.

(1): No I will not taboo that term, it belongs here.

/r/politics is over there →

Case: person who organized mass murder was put under trial by an outside group and executed.

Yet I hold that it was entirely ethically correct and proper.

Henry Kissinger organized mass murder.

The implication is there