In an insurgency, police are caught in the middle. How they are trained and equipped, who controls them, what their missions are, etc. pose massive problems for the counterinsurgent.

Ordinary crime and corruption are problems in Afghanistan (as is traffic control), so traditional police would have their hands full under any circumstances. In fact, the German training program was initially targeted on this mission set.

Then come the organized drug bosses and quickly overwhelm traditional police.

Then come the Taliban, AQ, whoever else and realy overwhelm the police. Remember -- the insurgent is not the counter-soldier, he is the counter-policeman. He doesn't want to win battles, he wants to impose control.

So now the police tend to become something that they didn't start out to be -- paramilitary forces, and in the process, lose the ability to do traditional policing functions.

Well, of course the army can fight insurgents, but there's also a problem with that: we don't want the military to be domestic enforcers. Posse commitatus and all that.

Now my head is starting to hurt.

But wait there's more. When I was working in the Afghan MOD, the senior leadership came in and started the "gotcha" round --
"didn't you say that unity of command is a principle of war?"
"yes..."
"so we need command and control of the police, not the MOI."
'now wait -- the ANA will eventually be an externally directed traditional military force, and police are not part of the military function"
"Are you nuts? We have a huge insurgency inside our borders...(gotcha!)"

Well, you get the idea.

In short, there are not clean cut solutions. Wish there were.