[annalex]

About the need for a sovereign, I believe that what Aquinas says amounts to a proper delegation of warmaking power to the government. What makes the delegation proper varies from epoque to epoque; today we insist on a democratically elected leadership with separation of powers, but in the Middle Ages a dynastic claim of sovereignty was probably the proper method. Aquinas explains what it gives us:

- proper separation between private grievances that may be adjudicated and national causes that cannot;
- unified military strategy through single leadership;
- protection of those unable to bear arms themselves.

Note that a war waged by a leader who doesn't represent a nation (a warlord) cannot, obviously, be just, and a leaderless guerilla war cannot be just because it exposes non-combatants with which the guerilla intermingle, to retaliatory violence.

[annalex]

epoque -> epoch

[A.J.Armitage]

Some of those considerations would be better described as matters of prudence. I guess I don't see as a much of a distinction between warfare and other violence as you do. I think mine might be the better perspective because of the nature of the war we're in. Look, for example, at the plane that crashed in Pennsylvania. Neither the attack nor, in that case, the defence was a traditional act of war. The people on the plane found out it was nevertheless, as Bush later said, an act of war and made a warlike response, without waiting for any other authority to give them permission.