 If possession by the five nuclear Powers is lawful until achievement of nuclear disarmament; if possession is the better part of deterrence; if deterrence is the better part of threat, then it follows that the practice of States -- including their treaty practice-- does not absolutely debar the threat or use of nuclear weapons.Judge Schwebel also holds that the principles of international humanitarian law such as proportionality in the degree of force applied, discrimination in the application of force between combatants and civilians and avoidance of unnecessary suffering of combatants, all of which antedate the invention of nuclear weapons, must also apply to nuclear weapons.He acknowledges, however, that it is extremely difficult to apply the principles of international humanitarian law with the practice of employing such destructive weapons; although not doing so, in his view, vitiates international humanitarian law.