[apetrov]

Unfortunately, there is only a ‘treatment’ group but no control group (aka non-repeatable treatment), so it's hard to draw conclusions from it.

Also, the Poland location could be another explanation: if your neighbor is Russia, with whom you have (let’s put it mildly) a long history, but you’re also a NATO member under the U.S. nuclear umbrella, you have plenty of reasons to appreciate the aforementioned country. Disclaimer: just another possible explanation.