It's just as likely that the Confederate States would have thrown in Early with England in Fighting World War I, (Because England Recognized them and helped them win Independence.) and as a result, Germany would have been defeated quickly. They wouldn't have had time to send Lenin to Russia, and that would have wiped out the Communist menace before it started.
So since we are predicting fantasy histories, I will argue that the Confederate Defeat in the Civil War caused over 100 million dead in the 20th century.
No, the Confederacy would have been way too busy taking advantage of Britain's & others' distractions by gobbling up their colonies in the America's.
And, by 1914, the Confederate slavocracy would find they felt much more akin to the German military empire than to an "effete" British monarchy.
Remember, the Confederate slave-power expressed its love and affection for Britain in 1861, by refusing to ship the commodity both British & Deep-South economies depended on: cotton.
So, there's no reason to expect a victorious Confederacy to be any less withholding in 1914.