Can the Treaty of Versailles be justified?

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

As a punishment:

With the War Guilt Clause, the Treaty held Germany accountable for its role in starting the War
The treaty was seen as a means of holding Germany accountable for its role in starting World War I. 20 million military personnel and civilians died in the War, 56% of whom were in the Allied countries. Hence, the Allies (especially French PM Clemenceau whose country had suffered the most) sought to impose penalties on Germany for their aggression and role in causing the conflict.

As compensation:

These 'penalties' were the reparations that Germany was required to pay to compensate the Entente/Allies for the costs of the War. The sum of £6.6 billion/132 billion gold marks was intended to cover the infrastructure damage, financial losses, and loss of human life. As Germany accepted blame for starting the War, the Allies believed it was their responsibility to foot the bill.
The land which Germany ceded to Poland also rewarded them for their role in fighting on the side of the Allies in the War.

To prevent future aggression:

Under the Treaty of Versailles, Germany's military was dismantled and reduced to a token force. The Allies believed that by weakening Germany's military (and also economy), they could maintain stability in Europe and prevent future conflicts.
The land which Germany ceded to its neighbours also granted security to the region and Germany's neighbouring countries. For example, the Demilitarised Rhineland created a buffer zone.
By imposing harsh penalties on Germany, the Allies hoped it would deter any future attempts by nations to pursue policies of aggression and territorial expansion.

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.