By the mid 1930's the Air Forces had largely convinced themselves and so the politicians bombers were carrying something approaching nuclear weapons, able to hit targets accurately, they could systematically wreck cities a few blocks at a time. Consider if in June 1940 Hitler wanted to totally destroy Britain, starting a bombing campaign with chemical and biological weapons.
The German public cheered Chamberlain at Munich. The USSR was the only state that expressed an interest in defending Czechoslovakia as per its treaty with them. Poland had friends, like the pact with France from the 1920's, like the treaties with Romania, again from the 1920's but its joining in at Munich made it a convenient scapegoat for others.
France signed a Treaty of Alliance and Friendship with Czechoslovakia on 25 January 1924. Strangely enough when Hitler decided to take parts of the country he convinced others to join in. The Poles were quite interested, the Hungarians also. The Romanians stayed out, they had an alliance with Czechoslovakia.
Munich agreement 28 September 1938, Poland demands Teschen, German occupation of Sudetenlands begins 1 October 1938 Polish occupation of Teschen begins 2 October 1938. Hungary annexes parts of the border area with Slovakia.
"Munich Pact : Annex to the Agreement
His MAJESTY's GOVERNMENT in the United Kingdom and the French Government have entered into the above agreement on the basis that they stand by the offer, contained in paragraph 6 of the Anglo-French proposals of the 19th September, relating to an international guarantee of the new boundaries of the Czechoslovak State against unprovoked aggression.
When the question of the Polish and Hungarian minorities in Czechoslovakia has been settled, Germany and Italy for their part will give a guarantee to Czechoslovakia.
Munich, September 29, 1938.
ADOLF HITLER,
NEVILLE CHAMBERLAIN,
EDOUARD DALADIER,
BENITO MUSSOLINI"
In February 1939 the Romanians received the German delegation, Romanian production was to be adapted to German requirements, it demanded a joint German-Romanian oil industry, to "respect German export interests" and to standardise armaments along German lines.
March 1939 is a key turning point, up until then Hitler had expanded on the premise of having all German speakers united under him. There was now a world wide shortage of modern weapons as all major powers up defence spending.
On March 15 1939 Hitler took over the other Czech provinces, making Slovakia a protectorate, Hungary annexes Ruthenia/Transcarpathia from Slovakia, gaining more territory in April
On March 16 Romania mobilised 5 infantry corps assuming they were next, which made the Hungarians mobilise.
On March 22 the start of Nazi press claims about atrocities against Germans in Poland.
On March 23 it was annexation of Memel and the surrounding area. And Romania signed the Economic agreement with Germany but managed to keep it as a framework document, rather than a set of specific proposals. The Romanian Air Force started buying aircraft, like Blenheims and Hurricanes.
On March 26 the Poles offer a joint German Polish guarantee for Danzig and a customs free transit route, road and rail, across the corridor. In response to Germany's proposals of extra territorial links and control of Danzig. The Polish ideas were rejected, in effect the German proposals became demands, with an or else attached.
On March 29 the British received a good summary of Hitler's directive to the army dated 25 March, detailing the idea for the destruction of Poland and the annexation of Lithuania, along with the claim this was to happen within a few weeks.
On March 31 Chamberlain announced that it would help Poland if it was threatened and needed to respond with force.
On April 1 Hitler ordered definite plans for an attack on Poland be ready for an attack on 1 September.
On April 6 came the announcement of talks to form an Anglo Polish alliance.
On April 13 came Anglo French guarantees for Romania and Greece.
On April 23 the British announced conscription.
On 28 April Hitler renounced the Anglo-German naval agreement and the non aggression pact with Poland. Before this announcement the German embassy in Poland was informed to give no encouragement for any attempt by the Poles to reopen negotiations.
Things continued to speed up from then on. The only credible non Polish force that could stop a German invasion was the Red Army, but Poland was sure if the Red Army entered it would never leave. That left Britain and France with you may win the battle with Poland but you will lose the war with us, given every country has examples of breaking treaties that meant convincing people they really would follow through and it seems they did convince all but two of Germany's leaders, Ribbentropp was irrelevant, Hitler was not.
23 August Molotov–Ribbentrop Pact signed, the USSR to gain the Baltic states, eastern Poland and parts of Romania. Also Danzig declares itself a free state, hoping to provide the pretext for a German invasion.
25 August Anglo Polish Agreement, Hitler postpones the attack.
The Avalon Project : The British Bluebook
German dispositions on the western frontier as of 26 August 1939 from north to south (numbers in parenthesis are the divisional Welle) *' indicates subordination,
HG C - Generalfeldmarschal Ritter von Leeb
5. Armee - General der Infanterie Curt Liebmann (HQ Münster, covering Dutch and Belgian frontier)
*Korück 560 (Commander Army Rear Area)
*Armee-Nachschubführer 561 (Army Supply Command)
*Armee-Nachrichten-Regiment 563 (Army Signals Regiment)
*Vermessungs-Abteilung 624 (Artillery Survey Battalion)
Attached Heerstruppen (Non-divisional Troops):
*Pionier-Regiments-Stab 504 (Engineer Regiment HQ)
**Brücken-Bau-Bataillon 550 (Bridging Battalion)
**Pionier-Bataillon 666 (Engineer Battalion)
**Pionier-Bataillon 46
*Panzerabwehr-Abteilung 543 (AT Battalion)
*Oberbaustab 16 (Construction HQ)
**Bau-Bataillon 42 (Construction Battalion)
**Bau-Bataillon 41
**Bau-Bataillon 26
**Bau-Bataillon 25
**Bau-Bataillon 83
V. Armeekorps (AK) - Generaloberst Richard Ruoff (Army Corps, covering the Dutch border Emden-Kleve)
*Korps-Nachrichten-Abteilung 45 (Corps Signals Battalion)
*Korps-Nachschubtruppen 405 (Corps Supply Troops)
*22. ID (1.) (Infantry Division of the 1st Wave)
*225. ID (3.) (Infantry Division of the 3rd Wave)
*Grenzschutz-Abschnitts-Kommando 9 (Border Sector Command)
**Grenzwacht-Regiment 6 (Border Regiment) (two battalions with six companies)
** Grenzwacht-Regiment 19 (three battalions with seven companies)
Festung Aachen (total 16 MG and 12 AT companies)
Grenzwacht-Regiment 26 (three battalions)
Grenzwacht-Regiment 36 (nine companies)
Grenzwacht-Regiment 46
Grenzwacht-Regiment 56 (two battalions with seven companies)
Grenzwacht-Regiment 66
227. ID (3.) (Belgian border south of Aachen (Eifel) under direct control of 5. Armee)
VI. AK - General der Pioniere Otto-Wilhelm Förster (Luxembourg border (HQ Trier)):
*ARKO 6 (Artillery Commander)
*Korps-Nachrichten-Abteilung 46
*Korps-Kartenstelle (mot) 406
*Feldgendarmerie-Trupp 406
*Korps-Nachschubtruppen 406
*Grenz Infanterie Regiment Stab 124 (three battalions with three MG and four AT companies, two artillery and one flak batteries)
*Grenzwacht-Regiment 112 (three battalions)
*Grenzwacht-Regiment 122
*MG Batallion 1.
*MG Batallion 2.
*MG Batallion 3
En route - 251., 253., 254., 263., 267., 269. ID (all 4.)
1. Armee - Generalfeldmarschal Erwin von Witzleben (Saarpfalz)
*Armee-Nachschubführer 591
*Armee-Nachrichten-Regiment 596
*Korück 590
IX. AK - General der Artillerie Friedrich Dollman
*ARKO 15
*Korps-Nachrichten-Abteilung 49
*Korps-Nachschubtruppen 409
*Korps-Kartenstelle 409
*Feldgendarmerie-Trupp 409
*25. ID (1.)
*33. ID (1.)
*71. ID (2.)
Gruppe Saarpfalz - General der Pioniere Walter Kuntze (as of 17 September XXIV. AK)
*ARKO 143
*Korps-Nachrichten-Abteilung 424
*Korps-Nachschubtruppen 424
*Korps-Kartenstelle 424
*Feldgendarmerie-Trupp 424
*6. ID (1.)
*9. ID (1.)
*36. ID (1.)
*Grenz-Kommando Saarpfalz (total of 26 infantry, 9 MG, 6 engineer, and 10 AT companies, 29 artillery and five flak batteries)
**Grenz-Infanterie-Regiment 125 (three battalions)
**Grenz-Infanterie-Regiment 127 (two battalions)
**Grenz-Infanterie-Regiment 129 (one battalion)
**Grenzwacht-Regiment 132
**Grenzwacht-Regiment 142
**Grenzwacht-Regiment 152
**I./Artillerie-Regiment 105 (three batteries 15cm sFH, motorized)
**I./Artillerie-Regiment 106 (two batteries 15cm SFH and one battery 10cm sFK, motorized)
**I./Artillerie-Regiment 108 (two batteries 15cm SFH and one battery 10cm sFK, motorized)
**I./Artillerie-Regiment 109 (three batteries 15cm sFH, motorized)
**MG Batallion 10
**MG Batallion 13
**MG Batallion 14
**Grenz-Pionier Batallion 73
**Grenz-Pionier Batallion 74
**Grenz-Nachrichten Batallion 74
XII. AK General der Infanterie Walter Schroth
*Arko 108
*Korps-Nachrichten-Abteilung 52
*Korps-Nachschubtruppen 412
*Korps-Kartenstelle 412
*Feldgendarmerie-Trupp 412
*15. ID (1.)
*34. ID (1.)
*52. ID (2.)
*79. ID (2.)
En route - 75. ID (2.), 209., 214., 223., 231., 246. ID (all 3.), 268. ID (4.)
7. Armee (Oberrhein)
*Armee-Nachschubführer 558
*Armee-Nachrichten-Regiment 558
*schwere Stellungs-Artillerie-Abteilung 216 (Heavy Fortress Artillery Battalion)
**Stellungs-Artillerie-Batterien 217, 224, 227 und 230 (Fortress Artillery Battery)
*78. ID (2.)
*212. ID (3.)
*215. ID (3.)
*14. Landwehr Division (205. ID as of 1 January 1940)
*Grenzwacht-Unterabschnitt IV/33 (one battalion with six companies)
*Grenzwacht-Regiment 76 (two battalions with 12 companies)
**MG Batallion 4
**MG Batallion 5
**MG Batallion 11
En route - 260., 262. ID (both 4.)
Both 1. and 2. Welle divisions were fully prepared for mobile operations by 26 August, 3. and 4. Welle divisions were fully capable in defensive positions.
1 September Germany invades Poland
2 September France Mobilises, eight days after the German mobilisation was effectively complete (albeit some units especially of the 4. Welle were still moving to their positions as of 2 September). Also, the active German army (1. Welle) had begun its mobilisation in March for Fall Grün and had never returned to peacetime manning, its French counterpart, the "force couverture" or active army covering force, went on alert and began recalling forces to the colours circa 22 August. The two French "armoured division", 1e and 2e DCR, weren't actually created until January 1940. On mobilisation six of the later DLC were actually horse cavalry (DC) and only two of the mechanized cavalry divisions existed, only two DLM (the closest thing to a panzer division) existed there were 17 active infantry divisions and 9 active motorised divisions in France, between them they only included 24 active infantry and 20 motorized infantry regiments. The 27 other infantry and 7 other motorized infantry regiments to bring them up to strength required at least three weeks of mobilisation. The bulk of the initial mobilization (serial A) was designed to man the fortresses rather than to fill out the field army.
Assuming that all the active units were immediately thrown into battle without absorbing their mobilisation cadres, that pits the equivalent of 15 1/3 French infantry divisions and perhaps the equivalent of two or three mechanized and cavalry divisions, against 26 German divisions in prepared fortifications. The French reconnaissance into the Saarland "succeeded" in getting as far as it did because the Germans had no intention of employing a cordon defence until the Polish campaign was resolved. Furthermore, the Germans knew the French mobilisation schedule well, it was no great secret, and knew that by the end of the month the French could have considerable forces deployed, so it was better to yield early in the month to minimize casualties and complete preparations for a possible stronger attack later in the month.
French forces in the Saarland as of circa 8 September was:
Corps d'Armée Colonial (CAC) (Colonial Army Corps)
12ème Division d'Infanterie Motorisée (DIM) (12th Motorized Infantry Division)
3ème Division d'Infanterie Nord-Africaine (DINA) (3rd North African Infantry Division)
1er Corps d'Armée (CA) (1st Army Corps)
2ème DINA
42ème Division d'Infanterie (DI) (42nd Infantry Division)
IVème Armée
9ème CA
6ème Division d'Infanterie Coloniale (DIC) (6th Colonial InfantryDivision)
4ème DINA
20ème CA
11ème DI
21ème DI
9ème DIM
23ème DI
5ème CA
15ème DIM
3ème DIC
Total of 12 active divisions: 4 DI, 3 DIM, 3 DINA, 2 DIC
French Mobilization
Active Metropolitan Army consisted of 33 divisions and 2 Spahis brigades:
In Metropolitan France (including Algeria and Tunisia)
7 Motorized Infantry Divisions: 1e, 3e, 5e, 9e, 12e, 15e, 25e DIM
10 Infantry Divisions: 10e, 11e, 13e, 14e, 19e, 21e, 23e, 36e, 42e,
43e DI
3 Mountain Infantry Divisions: 27e, 29e, 31e DI
3 Cavalry Divisions: 1e, 2e, 3e DC
2 Light Mechanized Divisions: 1e, 2e DLM
4 North-African Infantry Divisions: 1e, 2e, 3e, 4e DINA
4 Colonial Infantry Divisions: 1e, 2e, 3e, 4e DIC
2 Spahis Brigades: 1e, 2e BS
Of those, VIe Armée (Alps), was 6 divisions and 1 Spahis brigade:
23e, 27e, 29e, 31e DI, 1e DINA, 2e DIC and 1e BS
All others units were covering the North-East from Switzerland to Belgium.
Mobilization consisted of 39 réserve infantry divisions:
15 Infantry Divisions (série A): 2e, 4e, 6e, 7e, 16e, 18e, 20e, 22e, 24e, 26e, 32e, 35e, 41e, 45e, 47e DI
2 Mountain Infantry Divisions (Série A): 28e, 30e DI
1 North-African Infantry Division (Série A): 5e DINA
3 Colonial Infantry Divisions (Série A): 5e, 6e, 7e DIC
16 Infantry Divisions (Série B): 51e, 52e, 53e, 54e, 55e, 56e, 57e, 58e, 60e, 61e, 62e, 63e, 66e, 67e, 70e, 71e DI
2 Mountain Infantry Divisions (Série B): 64e, 65e DI
Scheduled mobilization plan (France, North Africa & Levant):
Mobilization Day (M) was 2 September at 00.00 Hrs
1) M+7: 41 divisions ("couverture")
36 DI
3 DC
2 DLM
2) M+12: 63 divisions
58 DI
3 DC
2 DLM
3) M+17: 83 divisions
78 DI
3 DC
2 DLM
4) M+22: 86 divisions
81 DI
3 DC
2 DLM
Situation planned as of M+22 (24 September)
North-East and Jura: 56 divisions
23 DI Active (17 DI, 3 DINA, 3 DIC)
19 DI Série A (15 DI, 1 DINA, 3 DIC)
9 DI Série B
2 DLM
3 DC
1 BS
South-East: 9 divisions
5 DI Active (3 DI Mtn, 1 DINA, 1 DIC)
2 DI Série A Mtn
2 DI Série B Mtn
1 BS
Interior: 7 divisions
7 DI Série B
North-Africa: 14 divisions
10 DI (81e, 82e, 83e, 84e, 85e, 86e, 87e, 88e DIA, 1e & 3e DM)
4 DI "Protection" (181e, 182e, 183e DIA, 2e DM)
5 Cavalry Brigades
DIA = Division d'Infanterie d'Afrique (mountain type)
DM = Division d'Infanterie Marocaine (mountain type)
Levant (Syria-Lebanon): 2 mixed Brigades
Total: 86 Divisions + 9 Brigades (+ equivalent of 15 Fortress divisions)
At the point of contact in the Saarland the French forces totalled 12 divisions under two separate army commands; the German, ten divisions, plus a division-size frontier command. The French offensive occupied two small salients of German territory jutting into France, that were not seriously defended, but never reached more than some of the covering outposts of the Westwall.
In theory by 24 September the French forces in the Saarland could have numbered as many as 56 divisions if the Belgian and Luxembourg frontier had been stripped of all troops and assuming that all the mobilisation forces could have been sent to the Saar front, which is unlikely. They would have been facing about 24 German division equivalents who had a month to occupy the fixed positions of the Westwall and prepared field positions. Also, by 17 September the Polish resistance was effectively at an end and German forces had begun redeploying west. At best there may have been a window of a few days where the French could have attacked with a superiority in numbers, but it seems unlikely they would have accomplished much.
3 September Britain and France declare war on Germany.
17 September the Red Army crosses the border, some fighting but the Polish Government orders no resistance.
2 November 1939 US Cash and Carry act signed into law
Hitler sided with Hungary against Romania in 1940 and more territory changed ownership. The second Vienna Award, including ceding territory to Bulgaria.
11 March 1941 US Lend Lease act signed into law.
I would like to see the western allied military moves that would keep at least parts of Eastern Europe out of Stalin's control, Hitler largely decided where the Iron Curtin was.