germany will side more and more with eastern europe against all those who abandon the EU.
It is not. Nationalists are very strong in east Europe. Way stronger then in UK. Why? Because big % of citizens of UK are not England natives, but people that moved to England in past centuries. East Europe is nationally homogenise. There is tiny % of people that dont belong that nation. Nationalists or you can call them also neo nazis dont glorify their country but their nation. If you have citizenship of their country but you dont belong to their nation they will push you away and denies you equal rights.
Every European country is supposed to side with those that are part of EU toward those that are out of EU. That is totally logical. But also every country that is in EU will have to present some standard's that we all together decide. That is how communities work. Nationalism for sure dont help here. But I am sure all EU countries will overcome that. Europe was continent of constant wars for 1000 years. That had changed when EU was formed.
nationalists in eastern europe are in truth communists pretending to be nationalists,
It is same all over the world. Central Europe, West Europe, East Europe. Difference is just that in East europe because of not that long democracy tradition it is much easier for them to manipulate people with fear and hate. They are just politics that want to seize government and control. Most dont have any really strong believes beside that. They just use hate and fear to get that power. All of them will call everyone beside them a communist. Even if the guy was born after communism ended.