This ECFR analysis argues the EU is facing a historic choice on enlargement – either move fast and bring in new members amid rising geopolitical tension, or risk losing influence and credibility on its borders. But the text also makes clear this is not a clean victory story. Enlargement is turning into a high-risk gamble, because the EU’s own machinery is slow, its politics are fragile, and its institutions are already under strain. Brussels wants a “big bang” moment. The danger is that the EU may not survive the shock.