When talking of a federal EU, people often use the "United States of Europe" comparison. But this is looking in the wrong direction. A better comparison, and inspiration, would be the multilingual, multiethnic and multiconfessional union of India. My piece:
Europe should draw inspiration from the Indian unionThe subcontinent was also once split into small states speaking different languages, but the Indian union has brought great success. As the EU and India strike a trade deal, there are wider lessons.davekeating.substack.com