The two-thousand-year-old just war theory states that resorting to war is only fair if there is a justifiable reason for it, that the principles of proportional use of force and fair dealing in war are respected, that all legal means and alternative measures have been weighed and exhausted earlier and that the ultimate goal of war must be peace. Moreover, it must be proclaimed by a legitimate authority, and all (foreseeable) damage must outweigh the (foreseeable) benefit that war would bring. The aim of my master`s thesis was to apply the mentioned theory to the war in Slovenia in 1991 and evaluate objectively its justness. I interviewed people who have had a more prominent role during the war and have a slightly broader, sociological perspective on it. The findings suggest that it is much easier to justify ad bellum criteria than in bello. It is a fact that in every war there are individuals who see an opportunity to quench their thirst for blood and often act out of arrogance. Only the prudence and reasonableness of some of the officers on both sides prevented the consequences that we have witnessed on the territory of former Yugoslavia in the years that followed. Only enough time distance, objectivity and access to all archived documents can create a true picture of what has been going on during the war.