Note that this may perhaps require a POD before 1900, depending on what scenario you go for. Imagine a scenario of a slightly different WWI (or "Great War", given how the outcome/subsequent history may butterfly away WWII as we know it), which is undeniably started by the Entente powers (some help would be useful here, anyways

), perhaps also slightly earlier (or later, if you will) than in OTL. However, this still won't change the power setups/arrangements, meaning Germany and Austria-Hungary will probably eventually lose this war, anyways.
In OTL, it was certainly elegant (though folly) after WWI to exclusively blame Germany for the war. However, if in this scenario the Great War is undoubtably started by Britain/France, it would make no sense for them to blame Germany for the start of the war - it would be a very obvious lie and everybody would know it.
Likewise, what would be the other psychological effects of such an alternate WWI?