Territorial changes after world war 1 led to the creation of new countries

A little known fact is that the USSR created a puppet state to act as a buffer between them and Japan which can technically be counted. During the Russian civil war Red army units and Japanese army units clashed, as well as Russian guerrillas. In  response, the USSR created an eastern republic as a buffer state, which prompted Japan to back off, since this was viewed similar to Latvia/Poland, a new country. It lasted for less than a year tho

The answer is crop yield.