What is Britain had not entered WWII

[ReluctantSamurai]

However, it is not impossible that the entire Japanese attack would have been re-thought if Britain had NOT been at war in the West and DID ramp up forces

After FDR's July 1940 embargo, what other course is available to the Japanese?

[Beskar]

After FDR's July 1940 embargo, what other course is available to the Japanese?

Not stab the sleeping giant in the eyes?

[ReluctantSamurai]

Given that Japan had only about 2yrs of oil reserves at that time, and that they had, as of 1941, military superiority, stabbing the "sleeping giant" in the eyes was practically the only recourse

[Seamus Fermanagh]

Given that Japan had only about 2yrs of oil reserves at that time, and that they had, as of 1941, military superiority, stabbing the "sleeping giant" in the eyes was practically the only recourse

I would add that their culture was as or more responsible though. Curtailing their activities in China and pulling back to Manchuria would, in some ways, have been a BETTER use of resources and would have likely cancelled the embargoes. 'Face' dictated that the Army simply could NOT do that and could not accept a slower approach to establishing their resource empire. It was the sense of insult engendered by US pressure as much as the economic impact of those sanctions that pushed an already militant government towards war.

[edyzmedieval]

Quite difficult not to get into it, given the geographical proximity. And simply ignoring the treaties signed with Allies would have been a no-no.

[ConjurerDragon]

Quite difficult not to get into it, given the geographical proximity. And simply ignoring the treaties signed with Allies would have been a no-no.

The western allies did exactly that at the start of WW2 by not immediately entering the war and starting an offensive into Germany within 3 weeks as Gamelin had promised the polish.

When we are in "what if"-land the western allies could simply have told Poland honestly that there is no way that they would be able or willing to do that and that Poland would fight alone for at least a month, or - after the signing of the Molotov-Ribbentrop pact - not before Poland would be completely occupied.

In that case the misguidedly stubborn polish government might be more willing to accept the german offer to accept the annexation of the Free City of Danzig (which was no part of Poland) and the connection of Germany with it’s enclave Eastern Prussia by a new Autobahn in addition to a renewal of the german-polish nonaggressionpact and to join the anticomintern-pact.

As the UK only guaranteed the existance of Poland, in that case the UK could stay out of a war with Germany without breaking their word.

And if the US and the western allies would have lifted the embargo against Japan for a withdrawal from China proper (not Manchuria or the former german colony in Tsingtao that they gained after WW1) then Japan could have decided to go north instead of south once Germany attacks the USSR - a decision that was vividly discussed in Japan.

[spmetla]

You're probably right in that if the UK were to not stand by Poland then France would probably not fought for them either. Either a quick victory over Poland or Poland giving up the Danzig corridor.

Would have been interesting though for the follow up Soviet land grabs. If Germany was not at war with France and the UK would those two nations have more overtly backed Finland? Having failed to stand up to a resurgent Germany would have been bad politically but people were not celebrating the start of a war in Paris or London in 1939 as they did in 1914.
The fear of the Bolsheviks was probably stronger than the fear of the nazis at this point, there could have been a war against the USSR over the Winter War or at the very least substantial material aid to Finland.

A war via volunteers or a naval embargo of the USSR would have been a favorable recourse for the UK and France to appear strong against totalitarianism to try and regain political credibility after the failure to protect Poland.

A later German war against the USSR without a western embargo or war would have been a very odd what if scenario. There would be strong support in the West for a war against the USSR and I think they'd more likely have participated in such a war alongside Germany than standing aside as the Germans took European Russia for themselves. I can't imagine France or Britain going to war against Germany in support of the USSR in any scenario.

The issue of Japan is certainly a tricky one, I can't imagine they'd fight the British Empire, France, and the Dutch if those countries weren't already at war with Germany and Italy. The forces that those nations could bring to bear against Japan if not busy with Germany and Italy would be quite tremendous. Yes, the IJN aircraft carriers and aircraft complement were superior to anything in the West at this point in the war but the sheer size of the surface and submarine fleets that those nations could field out of Singapore, Australia, and Indochina is tremendous.
This would also have put Nationalist China firmly in the camp of the Western Allies and without ground wars to fight in Europe and Africa they would have had substantial forces to put against Japan once mobilized.
I think it's more likely that Japan would have essentially sued for a favorable peace in China than to fight the Imperial nations in a bid to try and secure oil.

Japan would as you said probably have turned North instead and participated in a German attack on the USSR. The major question would I think be when would the Germans attack the USSR? Without a successful blitzkrieg campaign against France, the low countries and Scandinavia there would not have been the foolish over confidence that the Germans had in 1941.

Would have been odd for the US in this alternate world. An economic super power but still isolationist. A minuscule Army, no draft and certainly no US interventions outside the Americas.

Also, would a British Empire not tired by a second world war have given up India or any of it's colonies?

Interesting re-reading the OP and the (including my own) replies from over a decade ago in this necro-thread!