The Basque Army (Basque: "Eusko Gudarostea"), with 100,000 soldiers, was made up of battalions of different ideologies. It was well armed but poorly trained, and one of its most acute deficiencies was the absence of heavy artillery and an air force. Aguirre begged Indalecio Prieto and Manuel Azaña to send some aircraft. Historians agree that it was not a viable option because of the difficulties in breaking the Siege of Biscay. However, 40 to 50 airplanes were sent in different shipments, most flying over enemy territory. Others were sent across France and, after being disarmed, were retained or returned to Barcelona or Valencia in accordance with a "no intervention" policy. Another factor that contributed decisively to the Basque Army's defeat was its lack of a qualified general staff.