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
Tampico Affair destroyed to prevent their falling under U.S. control. By the spring of 1914, diplomatic relations between the US and Mexico were strained. US President Woodrow Wilson refused to recognize the presidency of Mexican General Victoriano Huerta, who had been installed as president the previous year after Huerta and the conservative rebel General Félix Díaz, a nephew of Porfirio Díaz, had signed the Embassy Pact with the approval of US Ambassador Henry Lane Wilson, who had since been removed by the president. The instability caused by the ongoing Mexican Revolution threatened US lives and economic interests in Mexico. Although Tampico was