Which kingdoms, little dictatorships and all sorts of fiefdom had World War 1 armor (and nothing more modern) at the time of the second war? I bet there was a lot because after the First World War all that equipment was sold off to little kingdom for which this firepower was real upgrade. In particular tanks and similar armored vehicles.
Wikipedia says only this: The volume of the arms trade greatly increased during the 20th century, and it began to be used as a political tool, especially during the Cold War where the United States and the USSR supplied weapons to their proxies across the world, particularly third world countries (see Nixon Doctrine).[9]https://origins.osu.edu/article/merchants-death-international-traffic-arms/page/0/1 says something about sales to China and Spain.