During The Twenties, the Weimar Republic directly promoted either the "collective guilt" idea or that "Germany was a victim of the Entente" and was fighting defensively (even if they declared war and invaded first) and that the other nations were jealous of Germany's rise and progress.
Historians with similar views (even, or especially from, America) were encouraged and directly funded in some cases, while those who questioned it were stifled and ignored, in a manner not dissimilar to the way the Confederate States manufactured and promulgated the "Lost Cause" thesis.
The dramatic collapse, the sudden revolution, and rapid changes in governments, states, borders that followed the peace further overshadowed and buried the circumstances that led to this conflict.
Likewise the new states that emerged had various political agendas.
The title, "the Great War" had previously been applied to The Napoleonic Wars.
The empires and nations that did come out , such as The British Empire and The French Colonial Empire found their power and uncontested influence weakened and challenged, both at home, and in their colonies, marking the beginning of the end of the age of empires that had defined the 19th Century, with the United States of America taking the role of a global leader for the first time, under President Woodrow Wilson.
The Soviet Union for instance argued that the war was caused by Capitalism and Imperialism, and of course it suited their agendas to blame everyone including Tsarist Russia, obviously, and claim that the only option is to end all nationalism and join the international brotherhood of Communism, and welcome Communist cadres and parties in all nations.
On the other side, politicians in Imperial Germany actually doctored their archives and destroyed some evidence and forged other documents.
The hope of the Concert was to contain the specter of revolution that they saw as a threat to national and domestic stability.
The gradual fracturing of that alliance towards the end of the century ultimately led to the return of revolution and domestic and national instability that in Europe would not heal until the fall of the USSR.