Will Eastern Europe cause the EU to break?

For those of you that follow EU politics, what are your views on the Eastern European countries that have joined the EU in recent years? Good or bad move?

In my opinion: for those countries to join looked very good on paper but in practical terms it has caused more division and problems for Western European countries, and the EU as a whole.

Reasons being:

- The standard of living in Eastern European countries is bad. And it's painful for them because they see higher quality of life in countries no more than a 2 hour flight away.

- That leads to immigration. If a certain place is crap you move, right? Well we've seen the result of that with Brexit, and the rise of nationalism in western european countries.

- Increased division: western european countries are only just getting used to the descendants of non white, non european citizens, despite the fact that many of those come from families who have held western european citizenship for hundreds of years. Add eastern europeans to the mix and it becomes volatile. Immigrants from eastern europe may look the same, but their way of thinking, cultures and attitudes to life are very different. (at least this is what it looks to me from the outside). Add the (engineered) migrant crisis to this and the situation becomes worse.

- Problems from the east are imported to the west: The eastern countries have always been volatile, both world wars started in eastern europe. Any notion of peace in this region is wishful thinking, the only way to keep the region stable is with many multilateral agreements between all parties.

- Involvement from other countries, mainly the US and Russia. Both these countries will protect their own interests and that makes eastern europe a flashpoint. Crimea (Russia) and military deployment in Poland (US). It doesn't help that many eastern euro countries are ex soviet.

15 years ago I was all for eastern euro countries joining, that view has turned Protected content . What I think should happen is that these countries should work on their own development from the inside, ideally with help from western europe before joining the EU. Also, the EU needs to apply stricter entry rules for countries to join and not try to make a United States of Europe.

The current situation just doesn't work.