Russians drink anywhere and everywhere. Including cops themselves. Polish and Slovaks too. Ukraine has war related prohibition, other then that? Where exactly eastern is it not allowed (or not completely normalized to the point locals would be surprised there is such law)?
Maybe they just don't follow that law, but public drinking is apparently illegal in Poland, Romania, even some cities in Slovakia apparently. Supposedly the police in Poland take a strict approach? (See wiki article "Drinking in public / By country")
