"It is forbidden to kill; therefore all murderers are punished unless they kill in large numbers and to the sound of trumpets."
–Voltaire (1694-1778)

A government that claims the authority to kill persons after they have been subdued, disarmed, tried, convicted and confined in prison has made a startling claim about the nature of political power. It claims not merely the authority to protect the innocent from violence, but the authority to inflict violence when no immediate threat exists.

It claims that the taking of human life, which it rightly condemns when committed by private individuals, somehow becomes morally permissible when committed by government agents. This is the fundamental contradiction of the death penalty: Government killing the helpless protects the living.

The Declaration of Independence offers a radically different understanding of government. All human beings possess natural rights, and governments are instituted to protect those rights. Government's just powers derive solely from the consent of the governed. Government is not the owner of our lives. It is our creature, established to protect rights that precede its existence. Its authority is limited, and it cannot legitimately claim powers that the people whom it governs do not themselves possess.

Individuals possess a natural right to defend themselves against an unlawful attack. They may use necessary and proportionate force to repel an aggressor. Because the people possess that right, they can delegate it to the government, including to a military for defensive purposes. Government's legitimate authority to wage defensive war is a moral and legal derivation of the people's preexisting right of self-preservation.