What accounted for the sudden, large gap between the "great powers" and the rest of the world that became so evident by the early 20th century?
There was a huge gap between the world powers and the rest of the world by the early 1900s. There are several factors that explain this. The world powers had a strong economy. By having a strong economy, these countries could build a strong navy. The navy could be used to protect the trade of the world powers. The navy would also be used to help gain additional colonies. It also could be used to help fight wars that could lead to more colonies. During this time period, having colonies helped expand the economies of world power countries. These countries would have more markets where they could trade their manufactured goods. They also could get resources cheaply from their colonies. These factors gave these countries a decided advantage and tended to make them stronger. Countries without a strong military, especially a strong navy, were at a disadvantage not only from a military point of view, but also from an economic point of view. Thus, a strong military and a strong economy helped separate the world powers from the other countries of the world.