Not a good idea to underestimate them. Nobody thought that they would get as far as they did economically either, even with the euro problems—which, like the current “refugee” problem, was a beneficial crisis designed for the purpose of power consolidation.
The whole purpose of the European Union is for the creation of a so-called “third power”.
I understand the main purpose of the EU was to prevent future wars between UK/France/Germany by binding them together. Unfortunately, that vision came at a time before they were considering existential threats from the middle east and Asia.