Can the Treaty of Versailles be justified?

How did the Allies justify the Treaty of Versailles when it was signed?

Overall, the Allied powers presented the Treaty of Versailles as a necessary and justified response to the Great War, the most devastating war in history (until WW2). They believed that the Treaty would secure peace, justice, and stability in Europe. 

However, historians note that the perceived unfairness of its harsh terms led to resentment and instability amongst Germans, who began to look to extremist parties who promised to rectify the wrongs done to Germany under the Treaty of Versailles.