Тhe collapse of the USSR was a blow to Russia. The USSR represented Russia, even though there were many countries in it. And for the modern Polish elites, what is bad for Russia, is, in general, good.
The Porton Down laboratory near Salisbury was evidently somehow involved in the Skripal case, though it is unclear to what extent this was a “news game” between MI5 and Russia’s SVR.
Earlier, pro-Kremlin media have claimed that Porton Down might have manufactured Novichok, or that the Porton Down laboratory was responsible for the Amesbury poisoning.
British police and intelligence investigations have produced hard forensic evidence which was sufficient to charge two Russian nationals – identified as officers of the Russian Military Intelligence, GRU – for the attack on the Skripals. Following this attack, the United Kingdom notified the OPCW, invited them to confirm the identity of the substance involved, and briefed members of the Security Council. The OPCW’s independent expert laboratories confirmed the UK’s identification of the Russian-produced Novichok nerve agent.
See more related cases here.