From June to December 1903, Schuyler was commander of the post at Fort Ethan Allen. from December 1903 to May 1904, Schuyler served with the 2nd Cavalry in the Philippines. He was assigned to duty with the Army general staff in 1904 and assigned as military attaché and observer with the Imperial Russian Army in Manchuria during the Russo-Japanese War and traveled to Shanghai, Peking and Mukden. Schuyler was present at the battles of Wafango, and Liaoyang. In December 1904, he traveled by the Trans-Siberian Railway to the Russian capital of Saint Petersburg and then Hamburg, Germany. From January to April 1905, he was on duty at the War Department, where he prepared reports about his experiences as an observer. Schuyler served as chief of staff of the Army's Southwestern Division from April 1905 to September 1906. In August 1906, he was promoted to colonel.