Then all the European combatants in the Great War would have collapsed in bloody exhaustion, and worked out some sort of Agreement to Cease Hostilities.
No Treaty of Versailles, no economic collapse of Germany, no rise of Adolph Hitler.
I trust you can take it from there.
"The Great War" would still be known as "The Great War".
I may be totally wrong, but I detect unlabeled sarcasm in the post you are responding to. I offer this because I almost typed an identical response to him before I thought it through and realized he almost certainly knew exactly what he was saying about the ‘That War To End All Wars thing sure worked out great.’