Nigeria's Boko Haram swore allegiance recently to the Islamic State of Iraq and the Levant (ISIL) in an audio message with French and English subtitles.
What most failed to notice was a few weeks earlier an "emissary" of ISIL sent a public invitation to the emir of al-Shabab in Somalia, Abu Ubaidah, urging him to do the same.
The emissary was Hamil al-Bushra, the nom de guerre used by two media outlets that have been described by Washington Institute for Near East Policy fellow Aaron Zelin as "official semi-official accounts" from ISIL.
In the message Bushra praised the "brothers in Somalia" and encouraged them to attack "inside Kenya, Tanzania, Ethiopia". He told Abu Ubaidah all that is needed to pledge loyalty to ISIL is for the al-Shabab media wing, al-Kataib, to issue an audio message.
Abu Ubaidah already pledged loyalty to al-Qaeda, reaffirming a long-standing allegiance with that group. The public invitation from ISIL through its semi-official channels may be designed to provoke a disruption within al-Shabab at a time when it has lost territory in Somalia because of a military offensive by African Union troops.