I have never shipped to, or from Slovakia but I understand, the geopolitical environment of this area of the world is a bit tense. This may have something to do with it?
If it is USPS Priority, the package is required to be tracked as well as provide proof of delivery. Those costs are usually passed from the postal-services that are involved. I would ask EU/Slovakian postal authorities why it is so expensive. I would guess there are “service” charges involved.
Shipping to places as close to the USA as Canada can be almost as expensive as this due to steep Canadian Post costs.
Its for sure not because the war in Ukraine, this shipping I had a long time ago, too. 
Any international shipping is very expensive in and of itself and each country has their own idiosyncrasies that can impact the cost as well. That’s why I don’t ship international anymore. The rates shown in your example look to be about what the going rate is. Probably not much different than anywhere else in Europe.