I do agree with all your points listed. Would it mean that France would stop being a colonial superpower? How about England? Does the sun finally set on the Empire? Would USA go into isolation policy even more?

What about all the countries that came as a result of World War One? Poland, Czechoslovakia, Yugoslavia, Hungary, Baltic States (Estonia, Litvania and Lithuania)?

Would there still be World War Two? Do Germans impose such strict terms on the Allies as it was imposed on them in?

I think France would have still possessed colonies. The Germans may have taken some (I would imagine they would take the Congo from Belgium). England would have been on the losing side but probably intact. Their confidence may have been shaken but I think they still would have been a great power.

US probably would have been just as isolationist.

I could see the Austria-Hungary of the 1920s to be a larger version of Yugoslavia of the 1990s. Ethic strife wouldn't have gone away. Maybe Russia would have championed the Slavic movements under the communists. Maybe the Balkans would have been communist sooner.

Poland would have become a satellite of Germany - think Grand Duchy of Warsaw from the Napoleonic era.

(I have an atlas of World War One and it has "what if" maps based on both sides war aims - the Germans would have maybe annexed parts of Belgium at the most, the rest of Europe would have been satellites or brought under German economic domination).

World War Two would have looked different. Perhaps a fascist Italy/France vs. Germany. Perhaps a German/Russian war. I'm not sure where England would fit in. I'm certain there still would have been a Japanese/American war, except instead of calling it WWII we would just call it something like the Pacific War.

Wow, I'm writing a lot.

@grumbledook - You bring up an interesting point about the US and Japan, which could have had pretty long ranging consequences. If the US hadn't become involved in Europe, all of the US forces and industrial might would have been focused on defeating the Japanese, likely bringing that conflict to a much swifter completion. I'm not sure exactly what consequences this would have had for the shape of the region. How would a more swiftly defeated Japan have effected the political and military situation in China? Would Mao have still come to power? Or would it have happened earlier?

One also has to wonder what effect that would have had on research into Nuclear Weapons. Without a Nazi regime in power in Germany, and without the US involved in a war with Germany, would the US have been pursuing nuclear weapons seriously? Would anyone? An interesting scenario indeed...

Good questions, DrOct.

What if the war in the Pacific happened sooner? If it happened in the 1920s the US, Japan, and Britain would have continued to build battleships instead of experimenting with aircraft carriers. How would that war have been different?

There is also the whole shape of the Middle East. Would the Ottoman Empire have survived? The countries in the ME were all formed after WWI. Perhaps you wouldn't have the Arab-Israeli conflicts.

If war in the pacific had kicked off in the 1920s, the Washington Naval Treaty would never have been signed:

The effects of the Treaty on the United States could not have been more different. The Treaty, coupled with the attack on Pearl Harbor on December 7, 1941 was a major cause of the United States Navy's conversion from a battleship fleet to a carrier-based force.[citation needed]

The United States was over the limits in capital ships when the treaty was ratified, and had to decommission or disarm several older vessels in order to comply. However, the only aircraft carrier in the US fleet before the treaty was signed was USS Langley (11,500 tons, 11,700 t), a converted collier. Not only did carriers have separate limits, but as an experimental vessel, Langley did not count against the tonnage restrictions. The US Navy thus had a free rein to build carriers.

In the 1920s the Department of the Navy had a low opinion of the concept of naval aviation despite (or perhaps because of) Billy Mitchell's 1921 success in using US Army Air Service bombers to sink the German battleship Ostfriesland. However, to comply with the treaty, two battlecruisers of the Lexington class still under construction, USS Lexington (43,500 tons, 44,200 t) and USS Saratoga(43,500 tons, 44,200 t), had to be disposed of. They were converted into carriers USS Lexington (33,000 tons, 33,500 t) and USS Saratoga (33,000 tons, 33,500 t), although that choice was only slightly preferred over scrapping.

source: wikipedia