Post-war peacebuilding is a delicate undertaking, and even the most promising process will face challenges and setbacks, purposeful as well as accidental. Examples include residual violence, coups d’états, terrorist attacks, delays of implementation, disagreement over what has been agreed, etc. Sometimes these challenges derail a peacebuilding process, but in other cases they are overcome allowing the process to continue more or less unaffected. The ability to withstand challenges should be an important indicator of the quality of peace and the success of post-war peacebuilding, and is now entering the conceptualization of peace and peacebuilding in the form of “resilience.” This paper starts from the need for a conceptualization of peace between negative and positive peace, and argues that resilience would be a useful concept. It then traces the argument back again, from adaptive cycle theory, via resilience, to peacebuilding. The tentative conclusions are very general, but I have not yet had the time to actually conduct a case study of Liberia.