The Anglo-Dutch Treaty of 1824 obligated the Dutch to ensure the safety of shipping and overland trade in and around Aceh, who accordingly sent the Royal Netherlands East Indies Army on the punitive expedition of 1831. President Andrew Jackson also ordered America's first Sumatran punitive expedition of 1832, which was followed by a punitive expedition in 1838. The "Friendship" incident thus afforded the Dutch a reason to take over Ache; and Jackson, to dispatch diplomatist Edmund Roberts, who in 1833 secured the Roberts Treaty with Siam. In 1856 negotiations for amendment of this treaty, Townsend Harris stated the position of the United States:The United States does not hold any possessions in the East, nor does it desire any. The form of government forbids the holding of colonies. The United States therefore cannot be an object of jealousy to any Eastern Power. Peaceful commercial relations, which give as well as receive benefits, is what the President wishes to establish with Siam, and such is the object of my mission.