The first thing worth noting about “war and capitalism” are the important intellectual traditions referring to the relations between these two terms, which operate in radically opposing ways. However, the main intellectual currents since the Enlightenment have posited an essential antipathy between these two concepts. Economic links were supposed to inhibit social conflicts and promote reciprocal dependencies, thus civilizing customs and promoting peace, both internally and among different sovereign entities. These ideas are coherent with world-visions with many ramifications, but often expressed under the form of an “ought-to-be”, not regarding real facts. An example is the work of Adam Smith, who argued that colonial trade was potentially a peaceful activity, good for all parties involved, whereas he simultaneously recognized that economic reality strayed considerably from such a rosy picture. The exact reasons for that remained somewhat vague, although Smith tended to blame monopolies and the mingling of trade with the exercise of sovereignty, as opposed to a peace-inducing model of open competition. This cluster of issues is treated here via the revision of the correspondent ideas by a number of important social theorists, including Adam Smith, Karl Marx, Max Weber, Werner Sombart, Thorstein Veblen, Joseph Schumpeter, Alexander Gerschenkron, Karl Polanyi, Fernand Braudel, Giovanni Arrighi and Michael Mann. The theories advanced by these authors are also contrasted with various important historical facts and trends, mentioned in the works of other relevant researchers, mostly historians, suggesting the convenience of keeping an open mind vis-à-vis the complexities, ambivalences and indeterminacies of social realities.