Proportionality (law)

Several distinct principles of law

Proportionality is a general principle in law which covers several separate (although related) concepts:
The concept of proportionality is used as a criterion of fairness and justice in statutory interpretation processes, especially in constitutional law, as a logical method intended to assist in discerning the correct balance between the restriction imposed by a corrective measure and the severity of the nature of the prohibited act. Within criminal law, the concept is used to convey the idea that the punishment of an offender should fit the crime. Under international humanitarian law governing the legal use of force in an armed conflict, proportionality and distinction are important factors in assessing military necessity. Under the United Kingdom's Civil Procedure Rules, costs must be "proportionately and reasonably incurred", or "proportionate and reasonable in amount", if they are to form part of a court ruling on costs.

A concept of proportionality that was testable in law was first developed in the High State Administrative Courts (Oberverwaltungsgericht) in Germany in the late 19th century, to review actions by the police. The proportionality test originated systematically with the jurisprudence of the Federal Constitutional Court, the Bundesverfassungsgericht.

In the European Convention on Human Rights, proportionality is one of main principles utilised by the European Court of Human Rights used for scrutinizing actions adopted by national authorities which restricts rights under the Convention the other is the margin of appreciation.

While the European Union has placed a consistent focus on the proportionality test in the context of policy issues, namely human rights, the proportionality test in the Australian context is a matter of constitutional interpretation with respect to legislative power under the Constitution. Unlike Europe, the proportionality test as a means to characterize whether Commonwealth legislation falls under a head of power under section 51 of the Constitution of Australia, has attracted divergent viewpoints, in which Kirby J has remarked that the 'test has not enjoyed universal favour'. However, Owen Dixon CJ made clear that 'the question is essentially one of connexion, not appropriateness of proportionality, and where a sufficient connexion is established, it is not for the Court to judge whether the law is inappropriate or disproportionate'.

The harm caused to protected civilians or civilian property must be proportional and not "excessive in relation to the concrete and direct military advantage anticipated" by an attack on a military objective. Luis Moreno Ocampo was the Chief Prosecutor at the International Criminal Court who investigated allegations of war crimes during the 2003 invasion of Iraq. He published an open letter containing his findings; in a section titled "Allegations concerning War Crimes", he elucidates this use of proportionality: