The M2A4 was the fourth variant of the M2 light tank family (formally Light Tank, M2) that served in the U.S. Army during the interwar period. This ultimately led to the development of the M3 Stuart family of light tanks later in World War II. The U.S. observations of the Spanish Civil War raised concern that their tank fleet, which consisted primarily of machine gun-armed M2A2 light tanks, was inadequate for the type of armoured warfare expected to occur in the future conflict. Initial recommendations included improving the armour thickness of their tanks and also introducing a 37 mm anti-tank gun. The first step towards implementing these modifications came on December 29, 1938, when it was ordered that a production M2A3 be modified into M2A4 light tank specifications for trial. After a series of U.S. Army trials and additional changes, the M2A4 was approved for production in May 1940, which would run until April 1942 with 375 tanks built. The M2A4 was the U.S. military's primary light tank when World War II started and would see service with the U.S. Marines in the Battle for Guadalcanal. The M2A4 would be replaced in production and usage by the M3 Stuart, which would achieve more combat fame in the European Theatre.

Introduced in Update 1.45 "Steel Generals" alongside the initial American ground tree, the M2A4 is a reserve light tank available for new players. The M2A4 light tank gives a good view into the M3 Stuart family of light tanks available for future research, presenting a fast and nimble vehicle with a respectable 37 mm anti-tank gun, though having subpar protection against close-range shots. While the M2A4 may not exceed in traits when coming up against its peers, these characteristics allow the M2A4 to perform flexibly, whether coming into a direct encounter with an enemy tank or outmanoeuvring the enemy to hit them in their weak spots with the 37 mm gun without being spotted.