Political map of the Arctic & the Far North 31 March 1854 (Opening of Japan): Across the Pacific, Japan had kept itself closed off from the world since the 17th century (Sakoku), restricting its contact with the West to a Dutch trading post off Nagasaki (Dejima). Determined to change this stance, the United States sent a naval expedition under Commodore Matthew Perry (Perry Expedition) to negotiate a treaty in 1852. Unable to counter Perry's modern steam-powered warships, the Japanese backed down and ended their era of isolation (Convention of Kanagawa).