The enclaves are mainly for sorting our your people and resources before anything would go hot. They are mainly for safety, security and economic development under conditions where if you are dispersed, you are subject to prejudice, extreme hostile surveillance, and a lack of proximity to a support network with appropriate backup. Local conditions, enemy activity, resources and priorities will determine whether or not any particular enclave is to be evacuated or defended, but not having enclaves in the first place is straight up suicide.
Even with high levels of mobility, you are basically still talking about shifting your population between relatively safe ground.
It is a rhetorical question over what level of resources an enemy is going to be able or willing to bring to bear on any particular target but there are plenty of historical references on how systems of enclaves work.
The enclaves are also an inevitable common sense thing, and the main functional difference between the enclaves and the squalor of refugee camps is prior preparation and resources. Being spread out among an enemy population is no way to raise a family or look out for your noncombatants.
Pleas before anyone continues to try and argue against this concept, look at how things went down in the Balkans and how it is now. Videos like this are dirt common:
http://www.youtube.com/watch?v=RnAGkg0XVng&feature=related Stuff like those murders happens to people on the edges of the enclave, or when they stay in enemy turf thinking they have a little live and let live deal going on. Even in the more closely monitored areas, public services, economic opportunities and other factors always get rationed in favor of the dominant party.
A lot of those Serb enclaves had to be evacuated under threat of NATO bombing and most of the rest were disarmed again, under the threat of NATO bombing, but not so much the threat of bombing of the enclaves themselves, but the nation (Serbia) that had been assisting the enclaves in their struggle against encirclement and domination by the Al Queda host population among nominally Muslim Albania.
The issue at the fall of Communism there was a great big race to loot government facilities and obtain weapons, and the fact that the central government had been nominally suppressing various ethnic hatreds for a long time, except even for that long time, it had been much more intolerant of ethnic Serb reprisals than Albanian "Muslim" crime. That Kosovo-Albanian-Swiss alliance is what had been a primary heron pipeline into Europe for Taliban controlled heroin. With the heroin trade went Islamo-facist influence except they were dealing with fairly corrupt people to begin with. So in proving their faith, they spend more time torching churches (and Christians) rather than going for that devout moderate Islamic faith thing.
