The world never recovered. 400 years of empire building, economic and political progress flushed down the toilet in twenty years. Followed by 45 years of communist infiltration, colonial wars and the whole Cold War.
And the burden fell mainly on us, and still falls on us as the Europeans are still incapable of pulling their weight. Only now our own fifth-column is on the verge of establishing a one-party woke corporate fascist state. All of which would not have happened except for WWI.
The most disastrous consequence of World War One was the collapse of the Tsarist regime and the rise of the Communists to power under Lenin, with Imperial Germany, in an act of unprecedented shortsidedness, facilitated by allowing Lenin to travel through its territory by sealed train to Petrograd in order to destabilise Russia in 1917.
Because of this, Communist Russia, and later the USSR initiated a progrem of demoralisation and subversion of the west at the cultural, political and economic level as Yuri Bezmenov set out in detail in his lectures and interviews given in the 1980s, and looking at the state of society now riddled as it is with objectively harmful and destructive ideologies that were designed to weaken and demoralise the West, we can see how disastrous it can be to allow evil and subversive ideologies to capture a powerful nation state and use the resources of that state to spread its toxic agenda worldwide.