Limit on capture of enemy property

The capture of enemy property in a lawful war is not to be thought [to be always] devoid of wrong, or exempt from the obligation of restitution. In fact, if you consider what may justly be done, it is not permissible to take or to hold property of greater value than the equivalent of the enemy's indebtedness, with this exception, that over and above that amount one may retain things necessary for a guarantee. When the danger is over, however, there should be a restoration, either of the things themselves or of their value, according to our discussion in the second chapter of Book II. What would be permitted in the case of property of persons at peace is much more permissible in regard to the property of enemies. There is, then, a certain right of seizure, without a complete right of ownership.

Now since a debt may be due to us either because of an inequality of possessions, or as the result of a [form of] punishment, the property of enemies may be acquired for either reason, but still with a distinction. For we have previously said that, by a debt of the former sort, not merely the property of the debtor, but also that of his subjects, according to the law of nations, is made liable, as though in the case of surety.