Final answer:
Napoleon's troops failed to reconquer Haiti because of a yellow fever outbreak and strong Haitian resistance, affecting his global ambitions.
Step-by-step explanation:
Napoleon's troops were unsuccessful at reconquering Haiti due to yellow fever, which decimated his army, and the fierce resistance of Haitian revolutionaries. The harsh tropical environment in Haiti, combined with the prevalence of yellow fever, took a heavy toll on Napoleon's troops. The diseases significantly weakened the French forces, leading to a high mortality rate.
After failing to reassert control over Haiti and restore the profitability of the colony, Napoleon faced significant financial strain and military depletion. This setback, among others, led him to sell the Louisiana Territory to the United States and abandon his New World aspirations, ultimately diminishing France’s global influence.