When America sneezes the whole world catches cold. It is attributed to an Austrian aristocrat, a Prince and definitely a word genius of those years, Klemens Wenzel Fürst von Metternich. Before and after the Napoleonic era he was an international diplomat of no little repute. He is among those credited with the fall of Napoleon dominance in Europe and beyond and crafting of the Metternich system. It was a system adopted by major European conservative powers against revolutionary movements, forces of nationalism in order to uphold the balance of power.
In fact, he meant that "when France sneezes, the whole of Europe catches cold." Of course another wordsmith crafted it otherwise. Hence the more popular" when U.S. sneezes the whole World catches cold."