I wonder what the Germans (and Italians) would have done had France not guaranteed Poland's security or declared war on Germany in Sept 1939. If France doesn't guarantee Poland nor declare war in Sept 1939 I expect Chamberlain's Britain may not either.
But Hitler can't safely invade the USSR and leave millions of potential French and British forces in his rear. So, the Germans need to go on another charm offensive, likely making a some deal with Britain and France.
Interesting concept. I was thinking of doing another thread for this subject in fact.
Another 3 months could have made a significant difference for France. They had a lot of new kit just coming online at the time of the BOF which wasn't quite ready yet or hadn't been given to the front line units yet. The D.520 had barely been deployed for example when the war started, the
VG 33 fighters, and
Bloch 152s* .
LeO 451 and Bre 693 bombers were all just coming to their first front line units. More promising aircraft like the VG-36 and
VG-39 were at prototype stage with series production just on the horizon. American aircraft such as more P-36s, and the P-40 (x 100), F4F Wildcat (x 81 for the Aeronavale), DB-7 / A-20 (x 64), Martin 167 Maryland (x 200)**, Martin 187 Baltimore***, Northrop A-17 (x 93), Vought Vindicators (x50) and Vultee 72 "Vengeance" (x 300) were also either on their way or in some cases had just arrived but not yet been integrated into their units. The French had also ordered 50 Dutch
Koolhaven FK 58 fighters, of which they only got 20 in time for the battle. The BEF may have also had Spitfires and Westland Whirlwinds available in another 3 months. I'm not sure if the French had ordered any aircraft from England.
The Dutch and Belgians would have had some Buffaloes (though maybe those were all going to the Far East?), some (36?) Fokker G.1, and more DXXI fighers.
Not to mention the French also had some fairly promising ground gear like the SOMUA S35 tank, which would have been deployed in greater numbers, and the S40 may have been available. Seeing Poland get destroyed by Stukas
might have inspired the deployment of more and better AAA into French units.
* Unclear if the 152s would have been any good, but the mix of Bloch 151 and 152 aircraft deployed to 9 'Groupes de Chassse' were still going through severe teething issues and being repaired and modified when the war started. Maybe they could have been sorted out, or maybe they could have been replaced by D.520s or P-36s. Same with MS 406 and 410.
** which had a 4% loss rate for the French during the war, best in the French Airforce. Later did very well for the British in the Med.
*** 400 ordered though they wouldn't be ready in 3 months!. These were very good bombers which excelled in British use and had one of the best records for bombers in the DAF.