Do you agree with Sikorski's assessment of Poles
Some Poles are indeed stupid enough to consider people who work in the EU traitors. All nations have their morons, Poland is no exception. The difference is that here in Poland there is a political party specially for those morons and there is media (Radio Maryja, TV Trwam and Nasz Dziennik) which attempts to exploit the ignorance of PiS voters.
Is it a national trait in your view?
No. But while we're talking about being traitors, Poles have a habit of not being traitors and hating traitors but of quickly forgiving traitors. Polonians have a very strong tendency to be exactly the reverse.