[109] When Britain and France went to war in 1793, the U.S. needed to determine which side to support.[110] While the differences between the Democratic–Republicans and the Federalists had previously centered on economic matters, foreign policy became an increasingly important issue, as Madison and Jefferson favored France and Hamilton favored Britain.[111] War with Britain became imminent in 1794, after the British seized hundreds of American ships that were trading with French colonies. Madison believed that a trade war with Britain would probably succeed, and would allow Americans to assert their independence fully. The British West Indies, Madison maintained, could not live without American foodstuffs, but Americans could easily do without British manufacturers.[112] Washington then secured friendly trade relations with Britain through the Jay Treaty of 1794.[113] Madison and his Democratic–Republican allies were outraged by the treaty; the Democratic–Republican Robert R. Livingston wrote to Madison that the treaty "sacrifices every essential interest and prostrates the honor of our country".[114] Madison's strong opposition to the treaty led to a permanent break with Washington, ending their friendship.