I live in a former Soviet Union country and I can confirm that. Since we've joined EU in 2004 things have improved really massively in pretty much every aspect. Sure, we are still way behind the old western countries, but comparing to other former Soviet Union states that did not join EU, the contrast is staggering.

Interesting but completely baseless new myth.

Preventing war has been an explicit aim of European integration going back to the beginning. From the Schuman declaration (1950, founding document of the ECSC): "The solidarity in production thus established will make it plain that any war between France and Germany becomes not merely unthinkable, but materially impossible"[0]. This principle has been widely accepted in Europe for the last 65 years.

You may of course disagree that economic integration is the main reason for the lack of intraeuropean wars since then (especially compared to the previous few millennia), but dismissing it as a "myth" is at very least least a surprising claim that requires some actual argument to back it up, and "new" is just factually incorrect.

[0] http://www.robert-schuman.eu/en/declaration-of-9-may-1950