ISIS on the offensive in Iraq

[Viking]

Has splitting up a country ever resulted in the peace it was supposed to bring?

Take Sudan, did splitting that country up really make the north and south any more peaceful?

Yep, right under your feet is an example. In 1814, Sweden waged a war against Norway. In 1905 they threatened to do so again (but didn't). They aren't doing any of that stuff any more. The split-up of the country was most successful.

The problem with South Sudan is that many of the same elements that made the South Sudanese seek independence from Sudan are also present within South Sudan itself: several separate fundamental group identities exist. Most or all of these groups even have their own languages.

If the Sami had had their own sizeable cities* in Northern Norway, problems could have continued in Norway as well after the split-up; because of the strong Sami nationalism such cities likely could have given rise to.


* i.e. Sami-dominated cities. Even today the largest Sami-dominated municipalities seem to have less than 3 000 inhabitants.