Translate the following English sentence to French:
"He not only asked the real questions as to why we should build Europe, who should be involved, and how it should be done, he also provided answers key to the future of a European Union embarking on an unprecedented enlargement."
Et comment ? Mais il y a apporté des réponses déterminantes pour l'avenir d'une Union appelée à un élargissement sans précédent.