Post Versailles Treaty there was a strong sense of disillusionment & anti war sentiment from the outcome f the Great War. A large portion of the voters came to think US participation had been a mistake. While the veterans were largely honored, the politicians who led to war became tainted. This allowed a combination of fiscal conservative & anti military Congressmen to sash the US defense budget in the early 1920s. The Army & National Guard were reduced to a thin cadre & naval construction largely stopped with ratification of the Washington Naval Treaty.
WI: the global political landscape were different enough the US voters would support a more robust defense budget through the 1920s. Not necessarily a huge army & oversized navy, but one large enough for decent training & doctrinal testing, and more important expanded weapons development & industrial mobilization preparation. The plan submitted by Army Chief of Staff Peyton Marsh is a example
Regular active) Army.......................500,000
Army Reserve (trained officer/NCO)...100,000
National Guard...............................750,000
More important is the robust R & D programs identified were to be closely coordinated with a industrial mobilization plan. That is a defense budget subsidy would pay industry to keep essential machine tools on hand & have preparations for rapid conversion of factories to arms production. Critical raw materials would be stockpiled. Industrial plans would be updated frequently to reflect advances in arms development.
So heres my question; how far could US weapons & doctrine development go before the Depression intervenes?
As a starting point consider the results of the thin R & D during the Pershing years in the 1920s>
Garand Rifle, selected for potiential production circ 1926. Limited production during the 1930s.
M1 105mm Howitzer tested & selected for production. Shelved & then reselected & produced for WWII with a modified carriage as the M2 Howitzer.
3" gun project. This covered a wide variety of cannon applications from AT to AA, to field artillery. Project was mothballed in the late 1920s. For WWII the data & gun plans were used for further development of AT guns for the Tank Destroyer Corps & tank guns for the Armored Forces.
Air cooled conversion of the Browning medium MG. Development was shelved & then revived again in 1939.
I could go on, but there were dozens of weapons & supporting equipment R & D projects on the table in 1919-20 that were swiftly canceled or never funded at all.
So, had a larger portion of these been properly funded in the 1920s, along with field testing for doctrinal development, how might the US Army been equipped when the War Powers Acts of 1940 triggered US mobilization that year?
For bonus points apply this same question to anyother major industrial nation of the 1920s. All or most slashed development budgets postwar &kept a mass of aging weapons on hand through the 1930s. Identify how one or another might be equipped had there been a robust arms development program in the 1920s.