As the map is not complete and I can not see the letter on the dot on China, it is China which was treated in this manner.
Explanation:
In the 19th century and the beginning of the 20th century, China was a very weak country, which was weird when taken in account the population it had and the vast resources it possessed. The problem was internal, and the economy that was primitive compared to the more developed countries.
The European countries used this, and through military conquests manged to conquer parts of China and divide it into spheres of interest. The focus was mainly on the coastal areas, as they were of huge economic importance, so pretty much all of the coastline of China was under the rule of European countries, which despite their disagreements, actually worked together against China.
