Factual comment removed

Question

In the question Did NATO promise Gorbachev not to accept membership applications from former Warsaw Pact nations?, which made a factually wrong claim (that the GDR joined NATO in 1990), I made a comment along the lines of...

The GDR did not join the NATO, ever. What happend there (in 1990) was that the GDR ceased to exist, and the FRG expanded to include the five federal states constituting the territory of the former GDR. That was an eastward expansion of NATO borders, but not the accepting of a former Warsaw Pact nation into NATO. If such a promise was made (which I won't judge in a comment), the first case of it being broken would be the 1999 inclusion of Poland, Hungary, and the Czech Republic.

This is written from memory, as the comment was removed without notification or explanation.

The OP actually edited his question to reflect this input, so it was helpful. I also feel it was not offending or violating any rules of conduct.

I would like to know why the comment was removed. If it happened because the OP edited his question, I would like to point out that SE gives badges for leaving helpful comments, and it strikes me as odd that such a comment should be removed by moderators.

Especially as later comments are discussing the very same subject.

Answer 1

In your case, someone flagged the comments as being no longer needed, probably because the OP has incorporated the information into their post. A moderator subsequently deleted the comments as flagged.

Comments are, by design, ephemeral. They are supposed to be subject to routine deletion if no longer needed. Thus, having a comment removed is neither a reflection upon you nor an indication of any rule violation whatsoever. If no explanation is given, please simply assume it was merely a clean up.

I do think that your comment remains informative despite the OP's edit, and I understand how it may felt unfair since a similar comment (curiously, made before the user flagged yours) was preserved. Since you actually posted this as two comments, I have taken the liberty of combining them and undeleting one.

Answer 2

There seems to still be some confusion here on the status of comments, so I should probably reiterate this point.

Comments are meant to be temporary.

If you're a fan of a particular comment, every day it survives is a good day. Conversely, you should not get too bent out of shape when its day comes and it disappears. I'll excerpt here from the canonical Meta.StackExchange answer on the question How do comments work?

When should comments be deleted?

Comments are temporary "Post-It" notes left on a question or answer. You should not expect them to be around forever: Once a clarification has been made, an edit added to the post to include new information, or the issue in the comment is otherwise resolved, it is subject to deletion. In reality, many obsolete or chatty comments remain untouched due to the high volume of comments posted, but this does not mean that they can't or shouldn't be deleted in the future.

Now of course in practice we as moderators do typically indefinitely leave up comments unless someone has a problem with them. But if its something that gets flagged, more than likely it will get deleted. There are also a myriad other reasons why a comment might get deleted, but "OP actually edited his question to reflect this input", as specifically outlined in the quoted passage above, is one of them.