Русско-англо-русский юридический словарь

mitigating circumstance Accompanying or accessory condition, event, or fact that (though not constituting a justification or excuse of an offense) may be considered by the courts as reducing the degree of culpability or liability of the accused. Such circumstances may include family or personal situations, and may help in attracting a sentence less severe than a typical sentence for similar offenses. (BusinessDictionary.com)

A cause of action is a combination of facts giving rise to a claim or right to sue in UK law. It provides the basis for commencing court proceedings in order to obtain an appropriate remedy by law. In other words, a cause of action is the justification for bringing legal proceedings. (FindLaw UK)

In U.S. criminal law, necessity may be either a possible justification or an exculpation for breaking the law. Defendants seeking to rely on this defense argue that they should not be held liable for their actions as a crime because their conduct was necessary to prevent some greater harm and when that conduct is not excused under some other more specific provision of law such as self defense. (Wikipedia)

An act of aggression is defined as the use of armed force by one State against another State without the justification of self-defense or authorization by the Security Council. (iccnow.org)