Q: In this task, a passage will be given and the goal is to generate a question about temporal relations based on that passage. A temporal relation describes the relation between two things with respect to time e.g., something happens/starts/terminates/... immediately/shortly/usually/... before/after/during/... something else.
 Your question should include an event, or ask about an event, and should not be a yes/no question.
Passage: More than 17,000 foreign troops disarmed tens of thousands of rebels and militia fighters in the biggest UN peacekeeping success in Africa for many years after debacles in the 1990s in Angola, Rwanda and Somalia. 
A:
What event has already finished?