That strategy is exactly how ISIS ended up with billions in US military equipment in the first place.
Now we’re in a bizarre situation where even though ISIS is said to be a uniquely terrible enemy, we support none of the forces that are actually being effective at fighting them - Assad loyalists, Kurds, and Iranians - while at the same time we support those fighting the ones who are making headway against ISIS.
We have no business getting involved in that mess, but if we must, the only sensible way to go is to arm the Kurds to the teeth and otherwise get the hell out. The Kurds are the only faction in the entire region which isn’t either an open enemy or constantly stabbing us in the back.
We should have never invaded Iraq and dislodged a dictator who was keeping the radical Islamists under control. Ditto in Libya. Gaddafi was no angel, but he kept the radical Islamists in check. Ditto with Egypt. We abandoned Hosni Mubarak, only to end up with Muslim brotherhood. We are very lucky Egyptian military took control.
Barack Hussein’s foreign policy favors the Islamists. He withdrew all troops too soon, and Iraq is now a disaster. If you think it is OK for letting ISIS grow in strength, then no need to invade Iraq again. Barack has failed in destroying ISIS. It will be up to the next republican president to fix the mess before it lands on our shores in a large scale attack which will make 911 look like a small skirmish.