Presuming the EU just appeared out of thin air in 1992/1993 and ignoring the predecessor organisations which were crucial for the formation of the EU is just wrong.

It's also not just about WW2, europe had at that point been at major war with itself in some form or another for well over a thousand years with only very brief periods of peace.

Of course by the 1990s it wasn't top of peoples minds because there had been peace for nearly 40 years, which is testament to the success of the original project, it doesn't mean the original goals had disappeared.