That’s the obvious conclusion as designer after designer decamps — even just temporarily — to Paris from New York, London or Tokyo. It’s as if the only way to be taken seriously is to show in the French capital (the latest example: Telfar Clemens), as if being a part of the grand finale of ready-to-wear month is the ultimate sign that one has arrived. “Paris, Capital of Fashion,” at The Museum at FIT, focuses on the spare-no-expense, color-drenched explosion of finery that took off in the Ancién Regime (from the 15th to 18th centuries) and hasn’t stopped since; “French Fashion, Women, and the First World War,” at the Bard Graduate Center Gallery, depicts how the French fashion industry persevered amid hardships and, by war’s end, gave the emerging modern world a pretty good idea of how it would dress. “Fashion is to France what the gold mines of Peru are to Spain” is the well-known comment by Louis XIV’s finance minister, Jean-Baptiste Colbert, who first organized craft workers into strictly regulated guilds that fended off imports. It was all about “shaping France’s identity and giving France a cultural and economic importance on the international stage,” said Sophie Kurkdjian,...