The principle of rights theory is the idea that in order for a society to be successful government must approach the making and enforcement of laws with the right intentions in respect to the end goals of the society that it governs. Members of society agree to give up some freedoms for the protection enjoyed by organized society, but governments cannot infringe upon the rights that citizens have been promised.
The principle of rights was proposed by Immanuel Kant. Kant saw a distinct correlation, yet difference, between the enforcement of law and the intent of law. In his mind, governments were entrusted with the ability to make laws by the citizens they governed in exchange for protection. Governments, therefore, had no right to violate that trust by creating laws with ill intent concerning the freedom that citizens had been promised.
The principle of rights is also applied to war. In order to be considered justifiable, the intention of entering into war must be right. In other words, according to Kant's principle of rights theory, it is not solely the outcome of actions that is important but the reasoning behind them as well, because if the intent is bad, then the outcome most likely is bad as well.