After the end of the Cold War, the world has experienced a more mono-polar power structure. In contrast to promises of a peaceful 'one' world, this seems not to have provided more international justice and security, nor reduced international conflict. Defense-related issues, long given minor attention in economics, have surfaced rather as a central mechanism in the current stage of globalization. Increase in military expenditures, the multiplication of wars, new generations of sophisticated weapons, and increased interest for defense stocks at the financial markets, indicate that a new type of relation between defense and economy has set in. The papers presented here investigate on what economics has to say on conflict, war, and terrorism today, a selection of sophisticated economic analyses of the theoretical and applied industrial, macroeconomic, fiscal-policy, financial market, regional, and alternative policies dimensions. Here, modern economics has a considerable and critical contribution to make.