The Coal and Steel agreement was the precursor to the forming of the EC, which later became the EU. The core belief that by fusing different economies together you prevent a war is still prevalent and the underlying necessity of the EU. This is, by the way, established historical fact. You can pretend it doesn't work that way in your head, but generally, everyone else will disagree with you.
But since you and History are not on good terms, perhaps you'll think about this a minute before shitposting again: For the first time in over 2000 years, the entire subcontinent has been largely at peace. I am ignoring Yugoslavia here, since they weren't in the EU. But everyone in the EU is at peace with each other. Not only that, it's so much at peace, that the mere idea of invading France is unthinkable. You'd get laughed out of the room. This is unprecedented as far as history records go. The EU is working. Babies like you don't remember a time when it was different. Heck, my parents even have just the foggiest memories of their first years during WW2. But it's not so long ago that you should dismiss the powder keg that Europe was at any given time in the past 2k years.
England vs. France. Germany vs. France. Spain vs. England. Austria vs. Spain. Prussia vs. Austria. France vs. Everyone. Those are all countries (Prussia being part of Poland now) that are member states of the EU. And the only competition they have currently is a political one. The PEOPLE like each other. A lot. Even if Merkel came up on TV and said "What ho, let's go invade France!" nobody would move a finger to help her.
Deny it all you like. Deny the significance. It is that ignorance that the EU is also protecting. You don't need to think for yourself if you don't want to, we'll even keep people like you save and sound. Whether you like it or not.