DR Congo may be big
The good DR Congo is nearly 1 million sq miles - almost impossible to police I would wager.
But we are talking about localised violence. Goma is a problem due to the proximity to Rwanda. But what happens there does not effect so much Bunia, which is close to Uganda or Kisingani which is miles away or Kinshasa which is close to the other Congo.
It would not be wise to assume an Iraq or Afghanistan. Nationhood as alluded to before is secondary to tribalism (and now I am shooting myself in the foot as there are some similarities with Iraq and Afghanistan) however the borders are more fluid and there is much more intervention around the perifery than people realise.
SS, I do feel strongly about this like I think you do. I have seen the evidence of some appalling crimes in DR Congo. All the thugs respect force. In 2003 there was a lot of action that took place that taught the drugged up AK47 totting twats that they could not bully the innocent. With a proper mandate and appropriate ROE an aggressive intervention good do wonders.
IMHO