Precipitating the change was the altered position of the United States. The Germans resumed unrestricted submarine warfare on February 1,1917, and two days later the United States severed its relations with Germany. Barely had the news of this American action reached Siam than Prince Devawongse, the minister of Foreign Affairs, wrote to Vajaravudh's private secretary for foreign correspondence, Phraya Buri, raising questions about the effect this American move toward a declaration of war would have on Siam's position.