In the late 1930s, in keeping with the Muslim Brotherhood's emphasis on actions rather than words, some members pushed for the organisation to form a military wing to take up armed struggle against British imperial rule, and some were already disobeying the Brotherhood's leadership and taking part in isolated clashes with the police. The Brotherhood's General Guide, Hassan al-Banna, felt that the Society was not ready to engage in military campaigns, and that those who wished to do so "might take the wrong course and miss the target". He advocated a more cautious, longer-term plan of forming groups of particularly dedicated members, called "Battalions", who would receive rigorous spiritual and physical training; once their numbers were sufficient, Banna felt, the Battalions would be prepared to engage in warfare. This would not involve terrorist or revolutionary action, which Banna rejected completely, but rather (and only as a last resort, if all peaceful strategies failed) openly declared war on imperial occupation. However, the Battalion system failed to develop on the scale Banna hoped for, and pressure from members for armed struggle against the British continued to increase. In 1939, this internal conflict developed into a major crisis, during which some of the most active cadres left the Society to form a rival organisation called Muhammad's Youth. The following year, as a result of this conflict, the Brotherhood created a military wing called the secret apparatus, which nevertheless remained mostly inactive during the war years.