Hello, I'm pretty sure this is a questions people already have given some thought - but the search function seems to have given up on me, so I thought I'd ask.
How long could you possibly make world war 2 last given the following prerequisites:
1. the war can't be a "cold war", there has to be military action between the participants (although it can be limited in scope or a stalemate)
2. Germany, Britain, USA and the Soviet Union stays in the war, none of those countries are "out"
Any advice appreciated.
Does the US have to enter the war at the same time as OTL?
Because one easy way to extend the war is to delay U.S. entry.
If FDR retires in 1940 - his successor might be a hard-line Isolationist. If it's Sen. Burton Wheeler (D-MT), who was in fact preparing to run if FDR stepped down, the U.S. will go to war
only if directly attacked, and will provide no aid whatever to any belligerent. This will end only when Wheeler leaves office - probably in 1945.
Possible narrative...
I'll drop in two divergences, both fairly reasonable probability.
1936 July: General Sanjurjo, intended caudillo of the Spanish military rebellion against the Republic, flies from Lisbon to Salamanca in the 7-seat DeHavilland Dragon Rapide that had brought Franco from the Canaries to Morocco. (OTL, Sanjurjo accepted the invitation of "daring aviator" Antonio Ansaldo to fly in Ansaldo's two-seater, but insisted on taking a trunk full of dress uniforms. The overloaded plane crashed after take-off, and Sanjurjo was killed.) The Spanish Civil War plays out roughly as OTL. Knock-on: anyone who would do that is romantic and impulsive. Sanjurjo, feeling that Spain owes Germany for help in defeating the Reds, brings Spain into the war on the German side.
1939 October: Colonel Gustave Bertrand of French intelligence, director of the code breaking center at Vignolles, gets promoted to a job in Paris. Bertrand's replacement, Lafourche, is a hard driver.
Back in 1930, Bertrand had acquired manuals and sample texts for Germany's new "Enigma" cipher system, which he turned over to Poland. This allowed the Poles to break Enigma. By 1939, German upgrades had re-blocked Enigma, but the Poles expected to re-break it. They gave all their work to Britain and France, and after the fall of Poland, the Polish analysts escaped to France, where they went to work under Bertrand's direction (in collaboration with GCCS at Bletchley Park).
Bertrand was not an energetic manager - he liked long formal lunches, attended by the whole staff and lasting well into the afternoon. Enigma was not re-broken till April 1940.
Lafourche pushes the staff hard, and the break comes in March.
Knock-on: Enigma decrypts provide clear warning of the German invasion of Norway. The Allies easily crush most of the German attacks, and the invasion is a debacle.
Consequences: (straight narrative hereafter).
The Norway debacle was a nasty shock to Hitler and the Wehrmacht.
Fall GELB ("Case YELLOW"), the attack in the west, was postponed from early May to June.
Then a second shock came in. The dazzling success in Norway, off the Enigma decrypts, was too good a story not to be spread. Neither France nor Britain had established the ULTRA security that existed later OTL; too many people wanted to brag. Nobody spoke openly, but bits of the story passed to friends, to mistresses, then to mistresses' friends and to their lovers, to friendly diplomats and then to foreign governments...
German intelligence picked up a host of clues, and a clever analyst assembled the pieces. The Germans realized that Enigma was compromised.
Fall GELB was delayed two months while the Germans reviewed Enigma, identified some of the weaknesses, and then issued new procedures and equipment.
This delay had an effect in U.S. politics. FDR had not declared whether he would run again. A third term would break an unwritten rule. But he also felt that his policies and abilities could be required to get the U.S. through the war period. With the war stalemated, and the Allies in good position, that fear abated, and FDR announced his retirement to the Democratic convention. The convention was up for grabs, as no serious candidate had yet stepped forward. The nomination went to Sen. Burton Wheeler (D-MT), who as an ardent New Dealer was an appropriate match for Republican Wendell Willkie. Wheeler was also a fanatic Isolationist.
Wheeler was elected. Willkie was a novice campaigner, and Wheeler was not handicapped by the third-time issue. Late in the campaign, Willkie adopted an interventionist stance, hoping to peel off some of Wheeler's support; but he only alienated midwestern Republicans. (The really strong interventionist element among Democrats was Southerners, who weren't voting Republican for any reason.)
Back in Europe -
Fall GELB began on August 10. The Allies had used the intervening three months to prepare more, but the sudden blackout of Enigma in July blinded them to key elements of German preparations. When the attack started, they were taken by surprise, after 11 months of "sitzkrieg".
They were also surprised by what Hitler had talked his allies into. Sanjurjo quickly agreed to join the attack; Mussolini was reluctant, but Hitler bullied him into it. The Spanish and Italian attacks were not especially effective, but they drew off much French strength at a critical moment.
The German attack was a decisive success. The hidebound French command could not cope with the fast moving German forces. By early September, Allied forces were in complete rout; the last Allied forces surrendered or evacuated by the end of September.
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The rest in summary:
Axis airpower drove Allied naval forces out of the western Mediterranean. The Axis took Corsica, invaded Morocco from Spanish Morocco, Tunisia from Libya, and Egypt from Libya. French North Africa fell by December. Intelligence from Enigma decrypts could have aided the Allies greatly, but they had none.
The Canary Islands had been reinforced in preparation for war, and an Allied invasion failed. The Battle of the Atlantic turned very bad for the Allies. The Axis invasion of Egypt failed though, and the Allies conquered Italian East Africa. Also the Axis march south from Morocco was stopped in the deserts of Mauritania.
President Wheeler in his inaugural stated that the U.S. would never fight in defense of another country's colonial possessions. This was clearly a green light for Japanese attack on the Allies in southeast Asia and the Pacific, which came in April. Indochina, Malaya, and the East Indies fell by May 1941. The Royal Navy was routed in the Indian Ocean and South Pacific.
Japanese fleets roamed out to occupy all of Melanesia and Polynesia (except American Samoa, the Line Islands, and the Hawaiian Chain - carefully respecting U.S. neutrality). Australia and New Zealand were forced to declare neutrality in July.
To all calls for U.S. intervention, President Wheeler responded that these events were happening 8,000 miles from the U.S. and were none of our business.
The Allies were at lowest ebb when Hitler overreached by invading the USSR in June 1941. Stalin however was not taken by surprise; he could see that Hitler was nearly done with the western Allies and ready to turn east. With Soviet forces on full alert, the Axis attack ran into a buzzsaw.
Soviet forces were still poorly organized and recovering from the Great Purge, so the Axis attack was successful - but not a
great success. Axis forces captured Crimea, Kiev, Smolensk, and Novgorod, but stopped well short of Moscow and Leningrad. Finland refused to join the attack, as her Arctic territories were exposed to Soviet
and western Allied attack (from Norway), and she would lose access to imports via Norway and Sweden.
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Summarizing faster.
1943-1944: The western Allies hold in NW Africa and Egypt. The Battle of the Atlantic remains grim, but Britain hangs on - barely. Japan makes no further major moves in Asia, concentrating against China, with occasional raids on British forces in the Indian Ocean. The Axis and USSR struggle, with neither side gaining ground. Britain initiates a major air campaign against German.
Reports of German and Japanese atrocities, Japanese attacks on Australia and New Zealand, and agitation by Communists and their sympathizers (reversed from 1940), shift American opinion strongly toward intervention. Wheeler agrees to a massive U.S. defense buildup, including deployment of 250,000 troops in the Philippines, but vetoes any expenditure toward intervention - he has just enough support in Congress to hold on - nearly all from Republicans, ironically.
In 1944, Republicans split on intervention, with the Isolationists narrowly retaining control and nominating Lindbergh. In a mirror of 1864, the Democrats repudiate Wheeler and adopt the name "Eagle Party", forming a fusion with interventionist Republicans.
The Eagle Party wins in a landslide, and on January 24, 1945 the U.S. declares war on the Axis.
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What about the Bomb? There has been no Manhattan Project. President Wheeler barred any cooperation with the Allies on such; the Allies have done what they can at Chalk River in Canada, but they haven't had significant budget. Probably Fermi, Szilard, and Wigner go there.
Thus the project has to start almost from scratch - and has to compete with the "conventional war", which needs every nickel, as it is much worse than in OTL 1942.
I'm not going to try to narrate the rest. The U.S. does have the advantage of four years of military build-up. It was not on the scale of OTL's war build-up, but a bunch of ESSEX-class carriers, Sherman tanks, B-17s, and so on are already in service. (The big ships are especially important, due to lead time.) The Army is up to 3.5M men, the Navy to 1.5M. (This is only 1/3 of OTL's max, but vastly greater than OTL's Dec 1941 level, and it's better prepared due to the steady growth over 3 years.)
Western Allied strategy:
Toward Germany -
Regain control of the Atlantic. This requires driving the Axis from NW Africa, with an overland campaign from West Africa. (1945)
Invasion of Spain, with secondary campaigns to take Sicily, Sardinia, Corsica, and the Balearics. (1946)
Invasions of France from Spain, England, and Corsica. (1947)
Secondary campaign into southern Italy and the Dodecanese (secure the Med). (1947)
Drive across France into Germany. (1947)
Invasion of Denmark from Norway. (1948)
Meet the Soviets in Berlin. (1948)
NOTE: lavish aid to the Soviets, all via Murmansk - the route past Norway is safe and Leningrad is not besieged. This saves
much shipping compared to Iran or Vladivostok, and also rail haulage.
Towards Japan -
This will get interesting. Presumably Japan is aware that the U.S. will go to war as soon as Wheeler leaves office. But meanwhile the U.S. will pour troops, planes, and ships into the Philippines. Does Japan wait for the U.S. or attack first? Until Japan attacks, Wheeler blocks U.S. intervention and Japan has a free hand in the South Pacific, but the U.S. has a free hand to build up the Philippines. It's not an obvious choice for Japan. Possibly Japan waits till it has finished its conquest of the South Pacific.
Also - the U.S. will have a Germany-first policy, but cannot ignore Japan, which is at war with the other western Allies. "Liberating" Australia and New Zealand will be a political priority. So the U.S. will be at war with Japan.
Assume Japan waits (which makes for a longer war). The Philippines and Guam are under siege immediately. Wake Island is a fortress. U.S. strategy has to be...
Hold Wake, neutralize the Marshalls (destroy all air/naval forces) (1945)
Drive the Japanese from the Indian Ocean. (1945)
Relieve Guam, neutralize the Marianas. (1945)
Secondary drive to link up with New Zealand and Australia. (1945)
Relieve the Philippines. (How long can 300,000 fully equipped and supplied troops hold out?) (1946)
Blockade and bomb Japan. (1947)
Invade Okinawa and Volcano Islands. (1947)
Invade Japan (or nuke 'em). (1948)
So there's my guesstimate - 1948. By 1949, the Allies have the Bomb, and that ends the war for sure.
