Actually, I'd argue that WW2 started on 11 December 1941. Before that it was a European civil war. All the combatants up to that point were European or their allies and almost all the battlefields were located in Europe.

It was only after Japan attacked the US and then Germany declared war on the US (11/12/41) that the conflict became truly global.

Mhaze

Not sure about that. While the non-European participants before Pearl Harbour were allies or subjects of European powers, they came from over 30 countries and five continents. There was fighting in South America, Asia and North Africa as well as Europe. I think that qualifies as a “world war” even without the involvement of the USA.

I like the concept of a European Civil War mhaze. Kudos.

Rhian,

Yes there was some fighting in South America, some in Asia and a lot in North Africa. But all of that was the European combatants carrying their strategic interests into their empires. All of those battles outside Europe (I said earlier that ALMOST all the battles were on European soil) were between the European combatants seeking advantage for their European war.

Pearl Harbour and then Hitler's decision to declare war on the US changed all that. Now we had the war including not just European states but the US, Japan, China, the entirety East Asia, the Pacific Ocean and the Arctic sea routes.

It became truly global. And the ramifications of victory or defeat were global

Humanity only has to overcome the Trilogy that makes up Stupidity to get to a stage of no war ! Wokeness & Religion & Greed !

8. Syria, where protests clamouring for political change, evolved into a civil war

Barack Obama ordered the overthrow of Bashar Al Assad in a covert operation named Timber Sycamore.
Probably a few more on your list which need further clarification.

Will Trump Deliver Peace? - Jeffrey Sachs, Alexander Mercouris & Glenn Diesen on the Duran
http://youtu.be/UqsGuRCnGPc