In 1844, William II of the Netherlands urged Japan to open, but was rejected. On July 8, 1853, the U.S. Navy sent four warships into the bay at Edo and threatened to attack if Japan did not begin trade with the West. Their arrival marked the reopening of the country to political dialogue after more than two hundred years of self-imposed isolation. Trade with Western nations would not come until the Treaty of Amity and Commerce more than five years later.