Legality and the use of force in international affairs

“War is a continuation of politics by other means”. This memorable dictum of Karl von Clausewitz (1780-1831) is generally upheld as an example of realism. Accordingly, we just have to accept it as a fact of life that nations are prepared to go to war in pursuit of their interests.

Clausewitz did not advocate war nor did he condemn it. He merely looked on war as a phenomenon of human activity that is worthy of study. The evidence available to him was overwhelming: sovereign nations are prepared to use force to further their aims.

This view was echoed in modern times by Hans J. Morgenthau (1985), the leading post-World War II realist theorist: "All history shows that nation states active in international politics are continuously preparing for, actively involved in, or recovering from, organised violence in the form of war."

However, there is an important aspect of Clausewitz’s observation that can be overlooked if we do not go beyond the initial, stark reality of his powerful message. Clausewitz regarded war as a lawful exercise of power by a lawfully constituted body, “the sovereign state”. The stress on the lawful use of force was an important aspect of his observation.

Our actions are guided by our beliefs, and in turn, it is our understanding that shapes our beliefs. Therefore it is essential that, periodically, we critically re-examine our understanding of events. In this instance we ought to examine the dictum that “war is a continuation of politics by other means”. There is the danger that in our actions we merely follow a self-fulfilling prophecy, and involuntarily accept that, although war between nations may be postponed, ultimately it is inevitable. In particular we ought to look at our understanding of the legality surrounding war between states.

Even before Clousewitz’s book On War was posthumously published in 1832, there were subtle changes in the laws, which circumscribed the way nations conducted their international affairs. The Congress of Vienna (1815) was one of the earliest practical attempts after the Napoleonic wars to establish a framework for co-operation between countries. The Congress itself created the first inter governmental organisation (IGO), “The Central Commission for the Navigation of the Rhine”.

Other such organisations followed. The Superior Health Council (1838) was established to control the spread of cholera, - with an inspectorate in Constantinople (Istanbul). The International Telegraph Union (1865) was the first IGO that the USA joined.

The gradual evolution of IGOs in the 1800s was aided, and indeed necessitated, by the burgeoning scientific and industrial activities. All the IGOs were in fact an attempt to regulate the laws between nations for very practical reasons. There was an increasing awareness that certain issues simply cannot be resolved by force but only by co-operation.

After World War I there was a genuine desire to create a framework for co-operation, which would make it less likely for nations to resort to war in pursuit of their interest. The League of Nations was formed specifically for this purpose in 1920. Unfortunately, the omens were not very encouraging.

Although the Covenant of the League was incorporated into Part I of the Versailles Treaty (1919), the treaty's primary intent was to enforce punitive measures against Germany. The Covenant itself had several weaknesses, notably its inability to control the actions of those who were outside the League. For example, when the Japanese invasion of Manchuria in 1931 was condemned by the League, Japan simply left and carried on with its aggression.

After World War II, the most comprehensive set of international treaties, known as the Charter of the United Nations, was signed in San Francisco in April 1945. Its purpose was, as stated in the Preamble of the Charter, "... to save succeeding generations from the scourge of war....".

Unlike the Covenant of the League of Nations, the Charter of the UN was conceived in a spirit of generosity. The United Nations Organisation, that became better known in its abbreviated form as the UN, was set up to facilitate the implementation of the Charter. The organisation itself was beset with problems right from the start. These problems had their roots in the emerging stand off between the communist block and the rest of the world. The Charter itself remained the bedrock of international law.