War is armed conflict among sovereigns or between sovereigns and those they govern.
 Just war
The conditions that make a war a "just war" are disputed. One proposed criterion is that a belligerent should have a reasonable chance of winning. Otherwise, it would be merely a futile gesture that would not change anything. The term "reasonable" is, of course, vague, and different people may have different ideas of what it means.
Libertarians have sometimes recognized that a person who tries and fails to overthrow tyranny should not be punished for it, if there is a way to protect him. Thomas Jefferson writes, "The unsuccessful Struggles against Tyranny have been the chief Martyrs of Treason laws in all countries. . . . [W]e should not wish then to give up to the Executioner the Patriot who fails, and flees to us." The U.S. Court of Appeals for the 4th Circuit noted that political offense exceptions were written into extradition treaties "to protect those people who justly fought back against their government oppressors to secure political change."
Lew Rockwell argues that the U.S. won wars in the past because "it fought far poorer governments. Today it loses because it fights populations â€“ people acting on their own, forming their own associations, using their brains to outwit bureaucrats, and cobbling together resources from underground markets. The market always outruns the planners for the same reason that guerilla armies usually win over regular armies. Decentralized and spontaneous associations of dedicated individuals are smarter and wiser and more committed than centralized and planned bureaucrats who follow their rule books."
- "Ethics Guide". BBC. http://www.bbc.co.uk/ethics/war/just/success.shtml.
- Ordinola v. Hackman, 478 F3d 588 (4th Cir. 22 February 2007).
- Rockwell, Lew (17 February 2006). "Iraq and the Democratic Empire". http://mises.org/daily/2148/Iraq-and-the-Democratic-Empire.