Al Shabaab, the militant Islamist group in Somalia, has taken over more territory over the past few weeks. With African Union and Somali troops stretched thin, the group has been able to steadily add to its holdings. But there is only so much al Shabaab can do to extend its reach. The group may have little choice but to dig in and wait , hoping that Mogadishu's foreign partners lose interest in the conflict before the army becomes strong enough to stand on its own. Al Shabaab has shown its ability to rebound from defeat before. In the wake of Ethiopia's initial invasion nearly a decade ago it did just that, gradually rebuilding its capacity by unleashing a relentless campaign of terrorist attacks and ambushes. The group eventually regained control over most of Somalia, becoming a formidable foe to the African Union Mission in Somalia (AMISOM).