Until the beginning of 1842 the struggle went in his favor; however, the resistance was put down by Marshal Bugeaud, due to Bugeaud's adaptation to the guerilla tactics employed by Abdelkader. Abdelkader would strike fast and disappear into the terrain with light infantry; however the French increased their mobility. The French armies brutally suppressed the native population and practiced a scorched earth policy in the countryside to force the residents to starve so as to desert their leader. By 1841, his fortifications had all but been destroyed and he was forced to wander the interior of the Oran. In 1842, he had lost control of Tlemcen and his lines of communications with Morocco were not effective. He was able to cross the border into Morocco for a respite, but the French defeated the Moroccans at the Battle of Isly. He left Morocco, and was able to keep up the fight to the French by taking the Sidi Brahim at the Battle of Sidi-Brahim.