Michael Totten
writes in
World Affairs Journal why the Iraqi government insists the U.S. not arm anti-ISIS Sunnis and Kurds.
The real reason for the government’s reluctance ought to be obvious: Iraq’s Shias do not want to arm Iraq’s Sunnis. They’d rather have ISIS controlling huge swaths of the country than a genuinely popular Sunni movement with staying power that’s implacably hostile to the Iranian-backed project in Mesopotamia.
Totten's conclusion below logically flows from his detailed analysis.
We don’t have to choose between ISIS and Iran’s revolutionary regime. They’re both murderous Islamist powers with global ambitions, and they’re both implacably hostile to us and our interests. Resisting both simultaneously wouldn’t make our foreign policy even a whit more complicated. It would, however, make our foreign policy much more coherent.
However, "resisting both simultaneously" could look like we've declared war on Islam, something few in Washington are prepared to do until events force their hands. For starters, you know Obama won't buy in.