I was reading the Wiki page about infantry support tanks and it said "For political reasons, the US Army was not permitted "tanks" in the years before World War II and so the tracked AFVs that it did develop were termed "Combat Cars" instead."
Some elaboration about these "political reasons" would be appreciated.
The answer to this confusing nomenclature is partly to be found in the National Defense Act of 1920. The US Army had an independent tank arm (the Tank Corps) at the end of WWI, but it became the victim of congressional restructuring and budget cuts. The rationale behind this restriction was that it reflected the conventional wisdom that tanks were first and foremost an infantry weapon.; procuring too many tanks would hinder their incorporation into the postwar infantry division. Section 17 of the 1920 NDA legally restricted tanks to the infantry and combat cars to be employed by the Cavalry. The officers in the interwar period that tended to see the tank as an offensive weapon tended to gravitate towards the Cavalry. Thus Cavalry "combat cars" tended to grow ever more tank-like, especially as European developments underscored the need for heavier armor and guns.
The Second World War and the fall of France forced a reevaluation of this policy. It had started in 1940 to concentrate armored forces into independent units, forming the nucleus of the wartime tank divisions. The Army had already sidestepped the NDA's provisions by establishing a General Headquarters tank battalion in 1938, attaching tanks directly to command units for use as either infantry support or offensive action. Despite this, the wartime Army retained some of this doctrinal baggage from this division of labor caused by the NDA. American tank design tended to emphasize speed at the expense of armor and armament (the legacy of the combat car), and US tank doctrine initially expected tank destroyers to be the main anti-tank weapon and conventional tanks like the Sherman to be primarily infantry support vehicles. Wartime experience forced a homogenizing process upon the Army and its tank arm evolved into a more general purpose armored force.
Sources
Cameron, Robert S. Mobility, Shock, and Firepower: The Emergence of the U.S. Army's Armor Branch, 1917-1945. Washington, D.C.: Center of Military History United States Army, 2008.
Johnson, David E. Fast Tanks and Heavy Bombers: Innovation in the U.S. Army, 1917-1945. Ithaca: Cornell University Press, 1998.
Zaloga, Steve. Armored Thunderbolt: The U.S. Army Sherman in World War II. Mechanicsburg, PA: Stackpole Books, 2008. Export a citation