The threat from militant group ISIL to East Africa has taken a dramatic twist. Somali jihadists Al-Shabab have effectively declared war on the group – calling on its supporters to kill anyone trying to join ISIL’s ranks. Experts say that’s a sign of weakness – and an opportunity for security forces.Not so long ago, for would-be jihadists across Africa and beyond – even to the United States – Al-Shabab was the group to join. It was the most effective of the Al Qaeda affiliates with several brazen attacks to its name but of late Al-Shabab has lost ground to African Union and Somali forces and, in the recruitment stakes, to ISIL which is now the militant franchise of choice. Even some in Al Shabab’s ranks, have switched over.In recent weeks, Al-Shabab defectors – including four commanders – have been killed. And this week, senior leadership called on its members to slit the throats of anyone seeking to join ISIL. Experts say this is a good time, to step up the fight against Al-Shabab. And in recent months, ISIL has established itself in north Africa ,striking in Libya, Tunisia and Egypt. It can also count Nigeria’s Boko Haram among its affiliates. East Africa seems a clear target for expansion despite Al-Shabab’s defiance.