Given the following passage  "In some rare cases, such as with Ethiopia and Qing Dynasty China, the local governments were able to use the treaties to at least mitigate the impact of European colonization. This involved learning the intricacies of European diplomatic customs and then using the treaties to prevent a power from overstepping their agreement or by playing different powers against each other.",  answer the following question. Note that the answer is present within the text.  Question: Who could be combative?
A:
powers