This questions can apply too in other contexts, such as speaking German among those whose first language isn't German, above all, English among those whose first language is Russian, Polish or German, for example.
Sometimes, the reason cited for using a "majority" language among minority speakers, e.g. Spanish in neighboring Portugal instead of Portuguese, Russian in Estonia rather than Estonian or English throughout much of Scandinavia over resp. Danish, Swedish and Norwegian etc... is ease of communication. The (not so) gentle problem here though is that ease may not necessarily facilitate accuracy, much less fluency not to mention aesthetic pleasure, in such circumstances. If Russians use their native languiage among those whose first language is NOT Russian and so forth, how can successful, not merely "basic" communication, be insured?
My numerous experiences with English at least, is that many Europeans are so used to jumping on the bandwagon of using it with foreigners at every given opportunity that the precision for which all language is intended has gradually become eroded to point, practically, of unrecognizability.
I could go on, but I'll simply stop with the thought that one ought to consider whether this is the fate to which we would like to consign the English language, or ANY language!
The vide above is an example how the media incited the whole violence. Newspapers had written that Russians had been planning to march in Warsaw during their independence day with flags of USSR and stuff like that. Imagine, a country who had been a cruel conqueror in the past sending ppl on the streets of the capital they had allowed to be destroyed by Germans in the country they had tried to subjugate (and sometimes still threaten, not necessarily directly). It was enough for some Polish hooligans, who decided to act. There were all in all only several USSR flags, but you can imagine. So it was the media's fault. I'm surprised they haven't suffered any consequences for that. I feel sad for the innocent Russians who suffered during the march.
But on the topic:
Yes, it is very likely that most Polish people will find speaking Russian in Poland offensive, but it is not the language itself, but the context, most of all.
To understand it you have to know our history. If you were sleeping during your history classes at school, this may take its toll here :P
Russians were conquerors. They tried to impose their language on Poles. Polish was, in certain situations and for many many years, before the Great (First World) War, forbidden. People had to protest against it, they were persecuted. Polish culture, literature and language were taught in secret, during secret gatherings. It was similar with Germans.
Now, we managed to get our freedom back. After WWII only partly, but we got our official language back. Still, Russian was obligatory at school. Do you see what's the conclusion?
It may be RUDE to speak Russian, because it could make a Pole assume that you treat him as a subject of the Russian Empire, of the yore, for that matter, but still.
It can be similar with German, but not so much, because those were Russians who controlled Poland after WWII, not Germans. The bottom line is, both nations wanted to destroy Polish independence, culture etc. Polish inteligentsia was persecuted. See?
BUT, it may not be the case in all situations. Examples follow:
1) If you are a Russian coming to Poland, we can assume that you can speak only Russian, or it is easier for you,so using Russian in obvious - I would never get offended - why should I? :) Russians and Polish people have the same Slavic soul, it is only that the forces in possession of those souls wanted one nation to devour and destroy/subjugate the other in the past. Of course, we talk about a situation of mutual respect, not assumptions that one nation SHOULD understand the other. I overheard a situation once when an older Russian guy was talking with younger girls. Rusian is a bit similar to Polish, only a bit, but it was enough for me to understand that he was referring to them as "silly/little Poles' - that was obviously an ill-done conversation.
2) A non-Russian foreigner assuming that Poles speak Russian and starting a conversation in Russian could be treated in a hostile or contemptuous manner - it would show his ignorance and lack of respect, even if they didn't know anything about Polish history. Current "lingua franca" is English. It used to be French, but now it is English. So as somebody has already suggested, start with English and then ask about other languages. If you can choose between English and Russian, choose English. The reason is mentioned above - Russians wanted to fight Polish language in the past. It could be similar with German, but the "Russian link" is fresher.
3) Younger generation hardly ever knows Russian - but can speak English more or less. The older generation, once forced to speak Russian, is likely to at least understand Russian, not necessarily produce it, as people forget things. They hardly ever speak English. However, as much as some of them would get satisfaction from using a language they learnt such a long time ago, some of them, remembering how the language was forced on us, could become indifferent or impolite. They may know the language, but it doesn't mean they WANTED to know it. Some people hate Russian because of the associations. One older person told me once that every time someone tries to speak Russian with them, they remember all the falsified books on our history, released and used to teach history at schools. So it is tricky here, it depends who you meet. Yet as I said, older people are unlikely to know English, so Russian may be your only option. And,well, what could happen in a worst case scenario?
4) Poles are very touchy about thinking of them as Russians. If you meet a Pole outside Poland, be careful about calling him a Russian. Even if you only mean to start a conversation, it may be the worst possible way. Polish and Russian are quite different, despite their similarities, and it can only show your ignorance or bad will. For the same reason, never ever ask if Poles use Russian/German as their language in Poland. Don't expect a friendly answer. Weird as it may sound, I have been asked such questions. They sound more or less like "So... you are a colony of Russia/Germany, right?"
So... as you see, there are specific contexts when using Russian or German (less likely) be tricky. It relates to situations, when you are not a German or Russian. I should also add that some people react strangely, if they don't know any foreign language. They ignore you :P I've seen it several times, but my observation shows that those people were, you know, stupid. Clever people will help you using gestures and general body language :)
