did nothing when Germans were suppressing the Warsaw Rising and destroying 90% of the city
Destroying 90% of the city wasn't the worst thing about it - cities can be rebuilt; the worst was murdering 200,000 of civilians by the German army, as well as Russian (Waffen-Sturm-Brigade der SS RONA), Belarussian (Schutzmannschafts-Bataillon der Sicherheitspolizei 13) and Ukrainian (Schützmannschaft Bataillon der Sipo 31) units.
By the way, this one thing makes me proud: there were Russian, Slovak, Belarussian, Croatian or Ukrainian SS units, but not Polish. There might have been some individual Polish citizens who served in SS but there was never a Polish SS unit.
Germans and their Russian, Ukrainian and Belarussian collaborationists slaughtered civilians in an organised and regular manner all over Warsaw. The Soviet army stood an watched, on purpose. Of course, from the political point of view, it made sense - Stalin waited for Polish patriotic youth, who would most likely cause him all sorts of trouble in the future, to be slaughtered. From the purely human point of view though, it was pure and undeniable
kurewstwo.
So, yes, surprisingly enough I find myself agreeing with Pawian on this one. Warsaw is one city in which Russians should refrain themselves from celebrating "liberation". There are tens, if not hundreds, of other cities which liberation Russians can genuinely celebrate; from Warsaw, however, they should rather discretely f*ck off.
It is a good thing that there were no incidents during the wreath laying ceremony by the Russian ambassador. Civilised standards should be kept. However, said ambassador should be called and have it explained to him that should the provocative actions of celebrating the "liberation" of Warsaw ever be repeated, his presence in Poland will be put into serious consideration.