Article: 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.

Now answer this question: Ethiopia and Qing Dynasty China were both able to prevent European powers from doing what to their agreements?
overstepping