I think a better solution would be a forced early morning exercise routine for the entire population. During these exercise routines, people must repeatedly chant the following verse:
WE'RE THE (Insert name of your tribe here)
THEY'RE THE (Insert name of your enemy tribe here)
WHOOT! (Insert name of your tribe here) RULE!!!
WHOOT! (Insert name of your enemy tribe here) SUCK!!!
GO (Insert name of your tribe here)!!!!
KILL THE (Insert name of your enemy tribe here)!!!
(Begin thumping chest)
UGA!
UGA!
UGA!
WE'RE NUMBER ONE!
Repeat ten times, then go about your business.
After about three weeks or so, I predict all the inhabitants will have sufficiently vented their inner monkeyness and they'll be willing to look at things with a fresher perspective.
If it works in the Holy Land, we can patent the Captain Haddock Original Conflict Resolution Therapy and export it to conflict zones all over the world. UN blue helmets can be deployed to lead the masses in their cheers. Peace, love and cute fuzzy bunnies will flourish across the Earth, guaranteed.
They say that only a fool continues to take the same actions expecting different results. It's time to try something new, and my plan is as good as any out there. Besides, my fee is very reasonable.