His political position waned after unsuccessful offensives in 1915, the German attack on Verdun in 1916, and the disappointing results of the Anglo-French offensive on the Somme in 1916. At the end of 1916 he was promoted to Marshal of France, the first such elevation under the Third Republic, and moved to an advisory role, from which he quickly resigned. Later in the war he led an important mission to the United States.