Inter arma enim silent leges

Inter arma enim silent lēgēs is a meaning "For among [times of] arms, the laws fall mute", but it is more popularly rendered as "In times of war, the law falls silent."

In Ancient Rome
This was likely first written in these words by  in his published oration , but Cicero's actual wording was Silent enim lēgēs inter arma.

At the time that Cicero used the phrase, was common. Armed gangs led by partisan leaders controlled the streets of Rome; nevertheless such leaders were elected to high offices.

Posterity
Amongst other Latin writers uses the expression in Letter 126.

In the US
's request for an opinion on the suspension of the right to ' during the resulted eventually in the following decision, in ' (1861), of , as a judge of the  for the  of :

"# That the president ... cannot suspend the privilege of the writ of habeas corpus, nor authorize a military officer to do it.
 * 1) That a military officer has no right to arrest and detain a person not subject to the rules and articles of war ... except in aid of the judicial authority, and subject to its control."

The United States' government explicitly referred to this maxim within its argument in the case , when it remarked (with an additional reference to Cicero) that "these [amendments of the Bill of Rights], in truth, are all peace provisions of the Constitution and, like all other conventional and legislative laws and enactments, are silent amidst arms, and when ."

The erosion of citizens' rights during were upheld in the Supreme Court case  (1943), which held that the application of curfews against members of a minority group were constitutional when the nation was at war with the country from which that group originated.  was a companion case decided on the same day.

In its more modern usage, the phrase has become a watchword about the erosion of civil liberties during wartime. In the immediate wake of the, the maxim was aired and questioned in the , with renewed force. The implication of the saying, as currently used, is in debate whether civil liberties and freedoms are subservient to a wartime nation's duty of self-defense.

In 1998, in All the Laws but One: Civil Liberties in Wartime suggested that "the least justified of the curtailments of civil liberty" were unlikely to be accepted by the courts in wars of the future: "It is neither desirable nor is it remotely likely that civil liberty will occupy as favored a position in wartime as it does in peacetime. But it is both desirable and likely that more careful attention will be paid by the courts to the basis for the government's claims of necessity as a basis for curtailing civil liberty. ... The laws will thus not be silent in time of war, but they will speak with a somewhat different voice."

In 2004,  used this phrase to decry the plurality decision in  which, in his view, upheld the detention of a  as an enemy combatant without charge or suspension of habeas corpus. "Many think it not only inevitable but entirely proper that liberty give way to security in times of national crisis that, at the extremes of military exigency, inter arma silent leges. Whatever the general merits of the view that war silences law or modulates its voice, that view has no place in the interpretation and application of a Constitution designed precisely to confront war and, in a manner that accords with democratic principles, to accommodate it."