Osama Bin Laden did not want the Somali Islamist group al Shabab to join the al Qaeda network.He criticised their leaders in a letter that was found in Abbottabad after he was killed in 2011,implying that they imposed unduly harsh penalties on "those whose offences are ambiguous".Al Qaeda's new leader,Ayman al Zawahiri,is less concerned with al Shabab's shortcomings.Less than a year after Bin Laden's death,Zawahiri welcomed al Shabab into the fold.
