This is because there are many more civilian deaths because of the unstable government and the fact that the civilians could get killed by the government and the rebels. Plus, there may be little or halfhearted intervention from other countries, so a lot of stuff could go down. The combatants don't need sophisticated weapons because these group hide and operate differently from foreign states, also the rebel populations hide within civilian populations so the government sometimes does indiscriminate killings. Obstacles: interests, inability to decide who to support, or whether to support either side, money and resources, its a CAP