On Wikipedia, I ran into an article talking about World War I to World War II and some of the adjacent wars before WWI as being a "European Civil War" or a "Second Thirty Years War". What is the scholarly basis of this? I saw a few names but it wasn't expecially concrete. There are listed citations from various authors but how rigorous is historicity of such a claim?
Clive Ponting, in his excellent "World History: A New Perspective" argued that WWI and the European part of WWII are, as the earlier big European wars, wars to determine who gets's to build a European Empire, and that they, as the earlier attempts, were inconclusive. (Or rather, WWII was conclusive in as much as the allies won, but a split between the Soviet Union and the democratic states meant that Europe instead was split in two "empires".
Although there is a case for seeing WWI and the European part of WWII as the same, as Germany was not conclusively defeated at the end of WWI and the treaties was used as an excuse to start WWII, if you do that extension you will have to more or less extend that to all wars in Europe from the middle ages, which makes little sense.
It makes sense to look for a pattern of world civil wars in the 1850s-60s as the Industrial Revolution began to change wars. Guns were being mass-produced, railways being put in war use, and better communications. Antagonists soon tried out these new methods.
China had an extremely bloody civil war over this period, its a good candidate for a foreign equivalent of the American Civil War certainly to the Chinese.
The Franco-Prussian War cannot be squeezed into the template of a European Civil War and the respective leaders and states had nothing in common except a border.
Ongoing European geo-political conflict can be expressed in many ways and needs a wider range of concepts than simply 'civil war'.