United States involvement in the Mexican Revolution with its diplomatic and economic rivals in Mexico, particularly Great Britain and Germany, meant that foreign powers affected the way the Mexican situation played out. When U.S. agents discovered that the German merchant ship, the "Ypiranga", was carrying arms to Huerta's regime, President Wilson ordered troops to the port of Veracruz to stop the ship from docking. The U.S. did not declare war on Mexico city but the U.S. troops carried out a skirmish against Huerta's forces in Veracruz. The "Ypiranga" managed to dock at another port, which infuriated Wilson. On April 9, 1914, Mexican officials in the port of
SMS Dresden (1907) guns. On 15 April 1914, "Dresden" steamed to Tampico on Mexico's Caribbean coast. That month, the German-flagged merchant ship arrived in Mexico, carrying a load of small arms for the regime of Mexican dictator Victoriano Huerta. The United States had put an arms embargo into effect in an attempt to reduce the violence of the civil war. The US Navy intercepted "Ypiranga" on 21 April. "Dresden" arrived, confiscated the merchantman, and pressed her into naval service to transport German refugees out of Mexico. Despite the American embargo, the Germans delivered the weapons and ammunition to the Mexican government on 28