With the advent of war in Europe in 1914, public programs were reduced, and Boulanger had to put her performing and conducting on hold. She continued to teach privately and to assist Dallier at the Conservatoire. Nadia was drawn into Lili's expanding war work, and by the end of the year, the sisters had organised a sizable charity, the "Comité Franco-Américain du Conservatoire National de Musique et de Déclamation." It supplied food, clothing, money, letters from home, etc. to soldiers who had been musicians before the war.