Well, I am of the opinion that the Germans were far too generous to the French after the Franco-Prussian War, complete disarmament and deindustrialization might have been sufficient reparations for the horrors the French inflicted upon the Germanies during the Napoleonic and, far more grievously, the 30-Years War. Split them into four parts, ban any sort of armed forces, destroy all the factories and mines, and burn all the vineyards.
Perhaps your opinion might change if you realize that essentially the Germans attempted to achieve that very end in the 1871 peace treaty. That was deliberately constructed to permanently destroy France as a military and industrial power. The removal of Alsace-Lorraine was intended to cripple French industrial power while the massive reparations were intended to drain French capital and prevent the redevelopment of industrial resources elsewhere. The problem was that the Germans didn't then have the industrial nous to do the job properly and the French were able to pay the reparations off quickly (within five years) and then switch to a program of redevelopment. Assisted by British capital investment which was an interesting reversal of the international situation to date.
So do you want to go to war against Germany now? After all, they're back together.
Different timeline of course and we can very well make the argument that the division into four occupation zones for a decade or so and the division of the country into two parts for forty years and change achieved the desired result. A declaration of war isn't necessary now because the desired result had been achieved. It's worth noting though that the Soviet Union stated that it would consider German Reunification a causus belli for a number of years. IIRC the constitution of the British Labour Party contained a clause opposing German Reunification, certainly well into the 1980s and it may be there today.
However, the point is that treaties, armistices, peace agreements etc are not constructed to be fair and equitable; there is no reason why they should be, they are dictated to the losers by the winners. They are constructed to achieve the strategic aims of the victors and they should be judged on the grounds of whether they achieve those ends. The problem with the Versailles Treaty was that the winners were a coalition that had divergent aims. France wanted revenge for 1871, they wanted their property back. They also wanted funding for the massive job of reconstructing north-eastern France and basically rebuilding the country. Britain wanted to make sure there wouldn't be another great war that would result in it committing a major land army to Europe, the US wanted an end to the Great Power system based on imperial possessions and Italy wanted to be considered one of the big boys.
Basically, by the time everything that people had discarded everything that they couldn't agree on and included everything they could, that lot boiled down to:
- Germany bore sole responsibility for starting the war and should be punished for doing so
- As a derivative of the above, it should be made impossible for Germany to start another war
- Europe should be repaired and the damage caused by the war remediated as soon as possible
For details of these negotiations and how the treaty environment evolved, I suggest you read
The Deluge: The Great War, America and the Remaking of the Global Order, 1916-1931 by Adam Tooze.
It's a masterly summary of the political, economic and industrial factors that led to the Treaty of Versailles and how that treaty inevitably led to the Great Depression. It's hard going, very heavy reading, but it is worth the effort.
So, judging on the basis of the three overarching aims, how did the Allies do?
I'd give them 50 percent on Aim 1. They did establish that Germany had been the overall culprit for the outbreak of WW1 internationally. Sadly, they didn't drive that home in Germany. A very good case can be made that in order to do this, Germany would have had to be occupied.
Complete Fail on Aim 2. WW2 broke out 20 years later and again, Germany was the culprit.
I'd give them 33 percent on Aim 3. The problem was that the Allies were deep in debt with the exception of the United States who was now the world's largest creditor nation. The UK wasn't too badly off; it owed the United States an eye-watering amount of money but most of it could be recouped from monies owed to it. The real problems in the Allies were France and Russia but nobody cared about Russia. The only way reconstruction could be funded was by reparations from Germany and Woodrow Wilson was unwilling to agree to the amounts required. A good case can be made that he simply didn't know how bad the damage was.
So, based on the only consideration that matters, how successful was the Versailles Treaty? 0.8 out of 3.0. That's a pretty dismal outcome. The massive fail was preventing Germany from starting another war and I honestly think that it was achievable only by forcing an unconditional surrender which the Germans knew was coming in December 1918. France and Britain knew it as well. America didn't.
It should be noted that the split up, occupy and reconstruct policy actually worked after WW2. It's probably one of the few examples of nation-building that has.