Red 6 said:
All well said, which is why it may have to be left to the future for the exact definitions of the large-scale conflicts of our own era.
The point made here about the Great War and the Second World War being defined as one conflict is apt, and some - perhaps many - historians are already transitioning towards that school of thought. I don't like it, but that's purely personal opinion. A soldier who fought in both World Wars might agree; a soldier born after 1919 who joined up to fight Hitler in 1939 might likely interpret it differently.
So who should "matter" more - those who are living it, or those who seek to define it years later? Whose objectives are "truer"?
Perhaps to answer that we have to answer the question: why define it at all? For a historian, it is to provide common nomenclature, ease of understanding, and indirectly make it more likely to generate interest in specific topics (and even sell more books, from a purely capitalist standpoint). For those living it, some of the same reasons - common understanding and generating interest for self-serving motives as well. Which isn't to denigrate those with self-serving motives, as we all have them. Historians live or die by selling books and soldiers live or die by convincing fat and happy civilians to give up health care, new roads and tax money to buy weaponry and pay wages for not just warfighters but the garrison-bound soldiers who outnumber them.
It comes down to integrating individual matters of opinion into widely held beliefs. I have an easier time believing that a conflict that included massive co-operation via Lend-Lease, Lease-Lend, regular conferences (and co-operation) of the leaders of the three largest powers on Earth (representing satellite nations probably including what - 60% of the world's population?) is fitting of the title "world war" than a series of what are in comparison conflicts of minor importance. In 1944, every man, woman and child in Britain and Canada was dutifully collecting "saucepans for Spitfires", undergoing (as Farley Mowat put it) "the horrors of sugar rationing" and dedicated to a national program of conservation all intended for a war effort that was part of their daily lives. Most Canadians today have no idea their nation is fighting a war, much less a world war.
So if it does, as I've just suggested, come down to integrating individual matters of opinion into widely held beliefs, I suspect the majority of opinion - at least in those countries where civilians really do get to be fat and happy - would be "war? what war?"
In other words - a world war involves more than just armies. A Canada in which a few thousands troops are in harm's way while the rest of the country doesn't even see them on the news is not fighting a world war. War is sacrifice, and from what I can tell, Canadians apart from those few thousands on the front line (and their families) are (knowingly) doing blessed little of that right now.
Edited to include the families of our soldiers. Also to add: amajoor's definition of World War III and World War IV doesn't hold water, in my opinion, if the component of national participation is added. Even those workers building AVGPs for General Motors or at the Peerless Garment Company making bush caps and combat pants were not "sacrificing", as they feely elected to go into those jobs, and did so I am guessing more for the money and less for the feeling of participation in a national imperative than Rosie the Riveter or Canada's Bren Gun Girls felt.
How many Canadians directly participated in the Cold War? Aside from a tiny Regular Force (who I think are to be respected as much as if not more than wartime vets, as there was little imperative for them to put on what in the 1970s was an unpopular uniform, not just because they were ugly but because of Vietnam and popular opinion) and Reserve Force augmentees (and even Army Cadets going over for REFORGER), how much "national effort" was there behind Canadian participation?
How much national effort went into even Vietnam (didn't the National Guard laugh off the whole war)? All these little wars being fought by the superpowers were done with professional standing armies, and the majority of people back home didn't have to lift a finger. The Soviet population suffered, but that was by design of the entire economy, not their individual desire to help the fighting men at the "front" of the so called WW III.