First of all, any force, whether it's peacekeeping, peace support, or counter-insurgency, whatever you want to call it, has to create the conditions where the belligerents are deterred and the civilian population is reassured. To do that, you need numbers, and you need quality density, as I mentioned before.
I'm going to give you some numbers. In counter-insurgency, to be successful you need 20 security force personnel—that can be internationals or local security forces—for every 1,000 people in the population. To secure Afghanistan, you need 500,000 security force personnel if you're going to be serious about it. Those are straight-on numbers. If you get a protection-of-civilians mandate and you're in a counter-insurgency environment, that's the kind of order of magnitude that you have to be thinking about.
If you can't do that—and a lot of times you can't—then you need to create what General MacKenzie talked about: UN protected areas. But they need to be properly resourced to protect the people who are inside those protected areas. If you can't do that, then you go to the lowest common denominator, which unfortunately is bringing these civilians as refugees or internally displaced persons onto your camp and protecting them there.
Those last two are actually the least desirable options. The bottom line is that you need to do what we did in NATO's case: flood the country with troops. Kosovo is another example. There were 40,000 soldiers from NATO in a postage stamp of a country. That completely stabilized it almost overnight. In fact, I recall visiting there, and you couldn't drive a kilometre without bumping into another NATO checkpoint. It created what I called at the time “belligerent gridlock”. You couldn't turn anywhere without bumping into a NATO solider.