Silas Deane was sent to Paris to begin negotiations with Vergennes, whose key objectives were replacing Britain as the United States' primary commercial and military partner, while securing the French West Indies from American expansion. These islands were extremely valuable; in 1772, the value of sugar and coffee produced by Saint-Domingue on its own exceeded that of all American exports combined. Talks progressed slowly until October 1777, when British defeat at Saratoga and their apparent willingness to negotiate peace convinced Vergennes only a permanent alliance could prevent the "disaster" of Anglo-American rapprochement. Assurances of formal French support allowed Congress to reject the Carlisle Peace Commission and insist on nothing short of complete independence.