Europe is however more likely than the US is to get bad quickly. It became a bad place to live for example from 1914 through 1918 and then again from 1939 through 1945 with, e.g., shortages of food and other life essentials while the US remained OK unless you were in the small fraction of the population that got drafted into the US military (and even then you would not have endured food shortages).

Although the creation of the EU was motivated in large part to prevent the recurrence of that sort of badness, the EU does not have the power to restrain the militaries of the individual European countries. Note that the EU was shown not to have the power to compel the Italian government that came to power because of the general election of March 2018 to adhere to EU regulations on deficit spending.

War within the EU is really really unlikely. A successful part of the EEC/EU is integrating the economies of its countries to such an extend that war becomes economically un-viable.

Nowadays war between France and Germany is close to as absurd a thought as a war between Calafornia and Texas is. It's not remotely comparable to 1900-1950.

Russia is the largest threat for European countries, but currently an attack on a NATO member seems unlikely.

That's what experts were saying before 1914, too: war is really unlikely because the economies are more integrated than they have ever been.

This is patently false. Theme in pre-1914 continental European press was monarchies struggling with independence movements, question of next Franc-Prussian conflict (because everybody was certain that peace between those two can't hold), and stability of Russian empire (that was at time engaged in bloody war with Japanese while being shaken by internal tensions).

Inter-war period was hardly one of economical integration, considered that most of European countries were engaged in economic war with other - eg. Poland had no economic exchange with its neighbours.

Tensions were very high in early 20th century Europe. If you're honestly saying this you either have not read history books on the era, or you know something very scary about Merkel that I don't.

[Citation needed]

There was no such thing as a European Union in WWI and II, which the discussion is about. That's why I don't understand how your comment is relevant here.

First there was no EU neither in 1914 nor in 1939.

Second, the US were not a nice place to live in 1861, while Europe was. Time changes.