In his model of the face of nature, Darwin showcases the interconnectedness of all species, together with the way in which changes to that face (the hammer blows) favor some species (wedges) while forcing out others.
ISIS is cruelly and provocatively murdering innocents. Naturally we are appalled and outraged. They must be brought to justice. Revenge, however, has proved to be quite a corrosive fuel for foreign policy strategy in a hornet's nest of a region even the word "quagmire" does not do justice.
Since its inception, U.S. Africa Command has consistently downplayed its role on the continent. Meanwhile, far from the press or the public, the officers running its secret operations have privately been calling Africa "the battlefield of tomorrow, today."
Iran blusters too much, and if it only means half of what it says, Israel should fear for its safety. However, much mitigates against military action, either by Israel alone, or in consort with the United States.