Another interesting aspect of tank development in the interwar years was the invention of the tank suspension. An American inventor by the name of ___________ Christie had designed a new suspension system for tracked vehicles. He tried to sell the idea to the American and British army, but he eventually worked with the Russians. The interwar tanks were almost obsolete from the day they were launched, but others took notice of how much faster Russian tanks were moving. The Christie Suspension was adopted by the major powers before WW2 started.

I was hoping to provide a Wiki link, but their "tank" article was a little light on Christie.

Anyways, WW2 is so fascinating at how quickly the technology changed. Machines designed in the Cauldron of Battle were obsolete 18 months later.