Delete: Pistol, Insert: Weapon, and Delete: all reference to 'Cavalry' - you then have a nutshell summary for the American attitudes that gave the world 7.62mm and wound up with 5.56mm (itself a sub-optimum combat calibre) being NATO standard to this day.
Well of course we did
for one thing we provided the BULK of NATO's small arms in the early days
M1 Garand's used by the USA, Italy, Norway, Denmark, Belgium, France, West Germany, Greece, Turkey, Netherlands, Portugal..... hell even the SAFN came in .30
The Browning .30 was almost universal as a AFV CoAx even in the UK until the 60's
Ferret, Saladin, Saracen, Centurion, Conqueror
Far easier to use the shortened .30US then to change bolts, links, clips and mags to suit and the Ammo could be remanufactured with new cases