They are fighting themselves, because they can, with help from us for the rest of this year, as Obama reauthorized fighting there by US troops. That's why Hagel is gone.
Obama is fighting smart. With Karzai gone, things will improve in Afghanistan, just as they will in Iraq with Maliki's ouster. He learned to no longer trust assholes, and he doesn't have to or need to. We learned fast how to reverse and stabilize situations in such places.
You can never get rid of cockroaches. You can control them, though. You can eliminate their presence, but they are always underground. Do you think the islamists have been eliminated in Egypt?
We need to focus on strengthening our finances, and taking care of ourselves here, and not waste money abroad other than helping those who want and can help themselves.