At least you can, now that both countries are in "Schengenland", go from one city to the other and back without any border checks. Does not necessarily mean there are no tensions, see this
http://www.reuters.com/article/worldNews/idUSTRE57K4K020090821 case of two EU member states. But it is amazing what has changed. In NE Saxony for example there is a beautiful historic park which used to be divided for many years - roughly two thirds are in Poland, one third is in Germany. Nowadays you can simply walk around there, without encountering anybody who wants to see your ID.
And sure, in those years several European countries had authoritarian regimes. Dollfuß and Schuschnigg in Austria, Pilsudksi in Poland, the coups in Estonia (Laidoner), Latvia (Ulmanis), Lithuania (Smetona) ... not exactly democracy at work. But no war and certainly no holocaust either. Similarly you may say that antisemitism in those years was not a "German specialty". But the nazi regime, umm, perfected it and took it from resentment to mass murder.
Interesting by the way that two of the three places referred to on these coins, Warsaw and Westerplatte, were and are widely known here. The nazi government covered them in its propaganda - in the flawed sense of "we Germans were provoked" and all that, but people learned about them. Now the Wielun attack was in a different category; the Germans basically bombed an undefended city. Would not have sounded terribly glorious, and was thus not really suitable for the war propaganda at home ...
Christian