First tow links on this board dealing with the same scenario.
WI Romania fights in 1940?
https://www.alternatehistory.com/discussion/showthread.php?t=145643&highlight=romania
1940. Romania decides to defend Bessarabia and resist the Soviets.
https://www.alternatehistory.com/discussion/showthread.php?t=248576&highlight=romania
Now for the
. What if Romania refused the demands?
One intersting note is that Turkey agreed to support Romania, would they have dared act if the Soviets really attacked?
What would the German, Italian , Turkish, Balken states and British reactions be?
A -
Beside war with the soviets,Turkey punts pressure on Bulgaria (So even if no war with the Soviets Turkey could still help)
Greece dose the same so Bulgaria is out.
Yugoslavia could do the same for Hungary and Bulgaria,so he have one more reason for Bulgaria to be out,and one for Hungary do be out.
Now for the big guns 1 - Germany,2 - Italy. 3 - British
3 - The can not do much beside some nice words they are at war with Germany,
1 2 the good option they put pressure on Bulgaria and Hungary not to get in the war,the very good they give weapons to Romania.
B -
Turkey,Greece,Yugoslavia turn a blind eye,Hungary and Bulgaria get involved and they together with the soviets split Romania among them self.
Now for the consequences:
For B : Romania oil production is destroyed,the Axis are unable to restore production,so no Operation Barbarossa,now he have bad option no 1 the soviets attack eventually a larger chunk of Europe ends under there Soviets after the war.
bad option no 2 the soviets don't get in and the allies are confuted with (a) accept the axis domination on the continent, (b) the allies are confronted with the prospect of a blood bath in Europe again they have tow options they accept and it or they decide to use weapons of mass destruction.(and keep in mind the the soviets might still change there mind at some point so add that to)
For A :
The war goes bad for the soviets Stalin as a paranoia crisis and Georgy Zhukov is shoot.
The consequences for the future war between Germany and Soviets could be disastrous for the soviets,on the plus side,a larger part of the could end up on the allies camp. on the negative side the war might take longer.
Now we have the soviets tanks,KV how entered service in 1939,T-34 in 1940 (September and prototype T-34s in January 1940),and the lights T-26 and the BT-series.
Now some of those tanks could see action and be captured by the Romanians which means that chance are they will be analysed by the Germans,how will learn form them.
(of course there is the option in which the Germans learn nothing,since Romania did quite well against the soviets so what is the point in learning from the soviets,this means the nothing much changes for the future war between the Soviets and Germans),but if the Germans learn this could mean the soviets do more bad in the war,the war last longer,(bigger chances of an a bomb been drop on Europe),or it is the same in duration but the soviets don't hold as much at the end of the war.This means the Allied occupied Germany is bigger,the Czech Republic is in the allied camp,so at least half of Czechoslovakia.
And then there a very good version in which Romania holds back the soviets how are unable to occupy Bassarabia and Bukovina.Romania doesn't get involved in Barbarossa,
the Germans learn enough.the soviets do bad enough so that S.C.E. Europe
is Neutral (Finlandizated) and allied after a while.
S.C.E - Hungary,Bulgaria,Czechoslovakia,Yugoslavia,Albania to list only the one how when to communism.are this time democracies.
also maybe Hungary and Bulgaria are also more neutral if not neutral. (edit:some might remain for a period Fascist)
O and Romania fighting could mean that Antonescu doesn't rise to power.(Especially if Romania dose well enough)
Edit real life probably a combination