Because of the well known destructive nature of war; more wars have been fought to prevent future wars than have not. E.g. The war to end all wars (WWI)
The EU was intended to cause the economic and political crisis we are seeing. A shared currency among such different exonomies is fatally flawed and requires a superstate solution - which was actual goal. Citizens would not knowingly vote for this, but as democracy in Europe is seen as a war risk, it is considered proper to suppress it. Of course this effort to prevent future wars will inevitably lead to a future war. Thus, I consider the break up of the EU as the only path to preventing war. Either way we're entering interesting times.