Geoffrey Blainey presents the beginning and end of war as opposite outcomes of a similar calculation. Diplomacy fails when opposing governments believe that armed conflict offers a better prospect of achieving their objectives than further negotiation. Such judgements depend on expectations about military strength, likely costs and the concessions an opponent might make. War therefore begins not necessarily because negotiation is impossible, but because the parties judge fighting to be more advantageous.

As a conflict continues, battlefield results, economic pressures and human losses can change those assessments. Governments may lower their expectations of victory or become more willing to accept a settlement. Negotiations then become attractive when the expected gains from continued fighting no longer justify its costs. The quotation reflects Blainey’s broader argument that war and peace are closely connected: both depend on how opposing sides assess their prospects. It offers a framework for understanding decisions, rather than a universal explanation of every conflict.