 Conducting exercises involving reservists is expensive, requiring compensation for lost wages, and it is difficult to call up then demobilize reservists again and again, which means that a nation that has called up reservists may be reluctant to stand them down again until the conflict is resolved.This is particularly true in the case of reservists in the sense of retired personnel, less true in the case of a standing force (e.g., the TA).In the prelude to World War I, the reluctance of the various antagonists to demobilize reserves once called up, due to the difficulty of remobilization has been held up as one of the causes why the diplomatic phase escalated so quickly to war.