Emmanuel Macron receives Donald Trump in Versailles to celebrate 250 years of American independence. And it's a first in half a century: no American president has had the right to it since Jimmy Carter in 1978. Between monarchical splendor and diplomatic symbol, Versailles is once again becoming the secret weapon of French diplomacy. In his international column, Mathieu Jolivet looks back on the history of this castle and Macron's strategy to make it a diplomatic asset.