This war was the beginning of the end for Maxamed Siyad Barre and his goverment. Their biggest problem was, they were completely clueless about international law and hadn't any form of long term strategy for "Somaliwayn".
There is no nation in this world who can invade another nations territory, regardless of common ethnicity in a certain region, without an international reaction. Even the super power Russia couldn't invade the Krim, without many sanctions, let a lone a poor third world country.
This war splitted the people and even worse, brought us more than a million refugees, with a population of estimated 3.5 Million people and a very high inflation. The government coudn't handle the challenges, which the Somali Republic had to face, as a consequence to this senseless war. It ended in oppressive and tribalistic regime, which fought for staying in power, instead of facing the real problems our country had.