This has probably been asked and gone over but..... In the Fall of 1939 when the French and BEF were lined up on the West of Germany and Germany was on the offensive in Poland with almost no troops in the West, why didn't the Western Allies attack and occupy Western Germany? Was it because deep down the Western Powers thought they could have brokered a peace deal with Germany after they were finished with Poland without any blood shed in the West? Or was it because they just didn't have the stomach for a fight? Did they not like the fact the Germany had the pact with Russia and feared the USSR aligning with Germany against the Western Democracies if they did attack Germany in the West?
It just seems like they had the perfect chance in the West while Germany was fighting Poland. I have a book "The Devil's Disciples" in which the author states the Western Allies thought Stalin was the bigger monster than Hitler circa Munich time and that they would have rather appeased Hitler then worked with Stalin, maybe hoping Hitler would keep his promise and smash Bolshevism while leaving the West out of it.
The simple answer is that the French weren't strong enough. Germany mobilized during the March crisis and had only partially demobilized. They mobilized for Poland on 28 August; French mobilization began at 0001 on 2 September. The BEF was not a factor, since the initial deployment did not finish until 19 October, long after the Polish Campaign was completed. At that, it only consisted of I and II Corps and 1, 2, 3, and 4 Infantry Division. Otherwise, the situation was: German dispositions on the western frontier as of 26 August 1939 from north to south (numbers in parenthesis are the divisional Welle) (courtesy AHF and Lexikon d. Wehrmacht) HG C Heersgruppen-Nachrichten-Regiment 639 (Army Group Signals Regiment) Panzerabwehr-Abteilung 652 (AT Battalion) schwere Artillerie-Abteilung 620 (Heavy Artillery Battalion) (one battery 15cm sFK and one battery 21cm Mrs) schwere Artillerie-Abteilung 649 (three batteries 15cm sFH) Armee-Abteilung A (Army Detachment A, Niederrhein, covering the Dutch Border from Emden to Kleve) Kommandantur der Befestigungen Niederrhein (Fortress Command Lower Rhine) *Grenzwacht-Regiment 76 (Border Regiment) (two battalions with 12 companies) XXVII. Armeekorps (AK) 16. ID (1.) (Infantry Division of the 1st Wave) 69. ID (2.) (Infantry Division of the 2nd Wave) 211 ID. (3.) (Infantry Division of the 3rd Wave) 216. ID (3.) XXX. AK Grenzschutz-Abschnitts-Kommando 9 (Border Sector Command) Grenzwacht-Regiment 6 (two battalions with six companies) Grenzwacht-Regiment 16 (three battalions with seven companies) 5. Armee 58. ID (2.) 76. ID (2.) 87. ID (2.) V. AK 22. ID (1.) 225. ID (3.) Kommandantur der Befestigungen 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 VI. AK 26. ID (1.) 227. ID (3.) 86. ID (2.) (opposite Perl, northwest of Merzig) En route – 251., 253., 254., 263., 267., 269. ID (all 4.) 1. Armee – XII. AK General der Infanterie 79. ID (2.) (Merzig) 34. ID (1.) 15. ID (1.) 52. ID (2.) (Saarbrücken) Generalkommando der Grenzrtruppen Saarpfalz 6. ID (1.) 36. ID (1.) (Zeebeiden) 9. ID (1.) Grenz-Kommandantur Saarpfalz (total of 26 infantry, 9 MG, 6 engineer, and 10 AT companies, 29 artillery and five flak batteries) Grenz-Infanterie-Regiment 125 (two battalions with 6 companies) Grenz-Infanterie-Regiment 127 (two battalions with 6 companies) Stellungs-Abschnitt 128 (6 infantry and 1 MG company) Grenz-Infanterie-Regiment 129 (one battalion with 6 companies) Grenzwacht-Regiment 132 Grenzwacht-Regiment 142 Grenzwacht-Regiment 152 IX. AK – 71. ID (2.) 25. ID (1.) 33. ID (1.) En route – 75. ID (2.), 209., 214., 223., 231., 246. ID (all 3.), 268. ID (4.) (Infantry Division of the 4th Wave) 7. Armee n (from the Rhine bend, inclusive of Karlsruhe, south to the Swiss border) 5. ID (1.) (Stuttgart? Later to XII. AK) 78. ID (2.) (Karlsruhe with one regiment opposite Colmar) 212. ID (3.) (southwest of Stuttgart) 215. ID (3.) (southeast of Mannheim) Generalkommando der Grenztruppen Oberrhein (17 September XXV AK) 35 (ID) (1.) (Strasburg) 4. Landwehr Division (205. ID as of 1 January 1940) (opposite Muhlhausen) En route – 260., 262. ID (both 4.) Total – 28 divisions plus 3 division-size fortress commands in place; 15 divisions assembling or en route The movement of divisions from Poland is harder to pin down. The earliest appears to be 62. ID on 19 September and 30. ID on 28 September. By 10 October the following had arrived from Poland: 4. Armee, III. AK, VIII. AK, XXII. AK, 3. ID, 17. ID, 23. ID, 56. ID, and 3. GebID, while 6. Armee had been formed and was placed under HG-B, which was formed 12 October. HG-B and 6. Armee, along with 4. Armee, took over the Neiderrhein from Army-Abteilung A, which was disbanded. By the end of October 2., 8., 14., 18. (on 25 October, after a two day train trip from Poland), and 28. ID. Also by the end of October 20. ID had moved back to Germany from Poland, but not onto the frontier. Thus, by the end of October 1939, 59 divisions were in place to defend the west German frontier.
French forces in the Saarland as of circa 8 September were: (courtesy David Lehmann and Louis Capdebosq) IIIème Armée (3rd Army) 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 Infantry Division) 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 00.01 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)
