The bombardment of towns, villages, and dwelling-houses is forbidden when these places have no military defence. If they have, bombardment is permitted, but under certain conditions. The commander who carries it on is bound to give notice beforehand to the enemy authorities, or at least to do everything he can to warn them. In the second place, bombardment must spare buildings dedicated to religion, science, and philanthropy, and also hospitals and centres for the sick and wounded, provided, of course—
(1) that these buildings have not been used for military purposes;
(2) that they are distinguished by some mark besiegers can see.
Consequently, the crimes which an army may commit, so far as bombardment is concerned, are as follows—
(1) bombardment of an undefended town or village.
(2) bombardment of a town or village without previous notice.
(3) bombardment of churches, monuments, scientific and charitable institutions, hospitals, ambulances.
Undefended Towns bombarded by the Germans
The Germans committed all these crimes simultaneously, but the least excusable and most cruel of all was the bombardment of towns which the enemy had evacuated, and to which, therefore, he could render no further aid.