[Nginx487]

I spot this demagogic argument from pro-Chinese position all the time: "they committed some crimes, so we have a right to do the same". Following that logic, they easily can justify their genocide with providing Holocaust as an example: "we just imprison and torture people, we do not burn them".

[hiq]

I think it's useful to directly use the word which describes this strategy:

https://en.wikipedia.org/wiki/Whataboutism

This makes it faster for you to refute their point, especially in front of other people who might be convinced by this argument at first.