The United Nations has more than 100,000 peacekeepers, serving in 16 missions on four continents.
Their goal is to protect civilians and maintain peace and security.
But their operations have caused controversy, including allegations of sexual abuse.
Demand for peacekeepers in conflict zones continues to rise and the UN is struggling to keep up.
Twelve months after world leaders pledged to strengthen and modernise peacekeeping operations, Britain is hosting a follow-up to see where things stand.
Defence ministers from more than 70 countries flew to London to discuss how to improve operations.
Presenter: Richelle Carey
Rosa Freedman - Professor of Law & Global Development, University of Reading
Mehari Maru - International consultant on African Union affairs
Jack Christofides - Director of Policy, Evaluation & Training at the United Nations Department of Peacekeeping Operations
Source: Al Jazeera News