What huge internal problems in Poland are you referring to? I'm genuinely curious, because the situation in Poland is quite stable (single party government), the economy is growing and we don't have migration problems like Germany or France.
Surely you mean an 'immigration' problem. Poland must surely have suffered for the massive emigration of young working people to the rest of Europe. We in the UK have been paying the pensions gap with the toil of Polish people for a number of years.