(CNN)ISIS is under pressure in parts of Iraq and battling a variety of adversaries in Syria, but it's metastasizing at warp speed elsewhere, most dangerously in Egypt and Libya. It also has support in Yemen, Afghanistan and Pakistan. And the leader of the group ravaging northern Nigeria, Boko Haram, has expressed his admiration of ISIS leader Abu Bakr al-Baghdadi. The savage killing of 21 Egyptian Christians in Libya -- all of them dressed in ISIS' trademark orange prison garb -- is another indication of ISIS' ability to take advantage of collapsed or collapsing states and of its growing presence in North Africa. Most significantly, the atrocity took place in Sirte, a long way from ISIS' first stronghold around Derna in the east of the country.
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Libya seems to be the most promising territory for ISIS to extend its reach
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It has also influence in Egypt's increasingly ungovernable Sinai
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From Nigeria and Pakistan, other groups seem to be forming various associations with ISIS
But as in Iraq and Syria, ISIS has launched an effective social media campaign in @placeholder.
The most intriguing development in recent months has been the desire of the Nigerian group Boko Haram to fly the @placeholder flag, literally and metaphorically.