Gadna is an Israeli pre-army military program to prepare high school students for their mandatory service. Gadna was created before the Israeli declaration of independence. During the 1948 Arab–Israeli War, trainees served as combatants. Until 1990, Gadna focused on instilling patriotic values in Israeli youth and encouraging immigration of youth to Israel. Nowadays, the program concentrates on increasing motivation to serve in the Army. As of 2007, an estimated minority of 16,000 to 19,000 11th grade pupils annually engage in squad-sized operations, night treks and shooting, with the promise of rewards for excellence when the youth join the Israel Defense Forces. Educators have criticized the program as "overly militaristic". The one-week-long program was revised in 2007 to include lessons in combat doctrine, the purity of arms and ethics in combat.