Well, in all fairness, we tried to use them, too. Of course, so did the Spanish kings 1300 years ago (when they called on the notoriously vicious Muslims in a regional war) and all they got for their money was having their kingdoms taken over and then being killed. I think Russia is experiencing the same thing right now.
The lesson is that there are some critters so vicious the only thing you can do with them is put them down. You sure can't make alliances with them.
True, but the point here is that the Russians are currently making common cause with the Terror Network against the US and its allies. They need to be called to account for this.