Notice how most of Iran and Eastern Iraq is dark green (Shia) and how the territory held by ISIS is light green (Sunni). Also note that Saudi Arabia has got bits of both divided by Wahhabism in the middle.
The basic problem is very clear. It is that millions of people in the Islamic world do not believe in free speech, freedom of religion, democracy, a secular state, free enterprise and human rights. Millions of Muslims also have a hatred for Israel and America that has no rational basis. - Mark HumphrysHe goes on at some length about what must be done, and he might be right, except for the "must" part. The only thing anyone "must" do is die, eventually.