Diplomacy without arms is like music without instruments. - Frederick II of Prussia

But a prince, when he binds himself, does not bind himself alone, otherwise he would be in the same position as a private individual. Instead, he exposes great countries and great provinces to a thousand misfortunes. Therefore, it is better that he should break his contract rather than that the people should perish.

(About the battle of Kunersdorf) "I shall not survive this cruel misfortune. The consequences will be worse than defeat itself. I have no resources left, and, to speak quite frankly I believe everything is lost. I shall not outlive the downfall of my country. Farewell, forever!"

Truth to tell, treaties are only oaths of deception and faithlessness. The jurisprudence of sovereigns is customarily the law of the strongest.