The essence of the concept of collective security stretches back to ‘time out of mind’ although it is only during the twentieth century that the particular contemporary meaning of the concept, with an emphasis on a wide collective, has developed. At the core of the collective security concept is the notion that if you, or your state, has an enemy your security is greater if you have an ally or allies who will support you against your enemy. Even the promise of support maybe sufficient to discourage aggressive acts by your enemy. My enemy’s enemy is my friend is a variation of this idea.

Examples of defensive alliances in the furtherance of security are lavishly scattered throughout pre-twentieth-century history. Here three examples are offered. This simple form of the essence of collective security, in the sense of the support of an ally, is seen in Classical times when Athens allied with Megara in the struggle with Corinth during the fifth century BC. In early modern times, Henry VIII, flush with his father’s finance, brimming with testosterone and keen to engage in warfare with France, took particular care to prepare for a possible attack from the ‘auld enemy’, Scotland, from the North. He anticipated the probability that France would recruit Scotland to dissuade and/or weaken an English invasion. France and Scotland did act in concert. On this occasion the Scots, at the main battle at Flodden in 1513, lacked the new ‘continental’ halberds of the English and, after a foolhardy charge, suffered a massive defeat. Bismarck assuredly understood the importance of allies as a deterrent to aggression by a hostile power, notably France after the Franco-Prussian war and the creation of the Second Empire in 1871. Aware that the new German Empire needed European peace and that France could be expected to be hostile to Germany for at least a generation, he fashioned the Dreikaiserbund (Three Emperors League) of Germany, Austria and Russia in 1873 and he sustained a series of alliances through the twists of circumstances and changes wrought by events until his resignation in 1890.

The occasion and springboard for the contemporary meaning of collective security, in the twentieth century, where emphasis on the word collective, that is, a wider international involvement, was the experience of the First World War, the first fully ‘industrial’ war and a war on a huge scale. Even before its completion, plans were considered for an international organisation that would both provide formal procedures for the settlement of disputes between states and the promise or possibility of concerted action against states that acted aggressively. Sir Edward Grey, the British Foreign Secretary, is attributed with initiating the idea and a committee in the Foreign Office worked on plans from 1916. American President Woodrow Wilson, who was influential at the post-war peace conference, supported the plan with enthusiasm. Each of the five peace treaties signed at Versailles, 1919-21 had at their start the Covenant of the League which began ‘The High Contracting Parties, In order to promote international co-operation and to achieve international peace and security … Agree to this Covenant of the League of Nations’. Although the League settled minor disputes, such as the Aaland Islands in 1920 and Upper Silesia in 1921, most disputes were settled by other means and when more major issues arose, notably Japan’s invasion of Manchuria in 1931 and Italy’s invasion of Abysinnia in 1935, the League imposed limited sanctions in the latter instance, the League was ineffective in the protection of states from aggression. Germany had been a member of the League only from 1926 to 1933 and Hitler’s repeated flouting of the Treaty of Versailles and the League will be known to many readers.

The failure of the League resulted from weaknesses in procedure, such as the requirement for unanimous votes, the absence of some of the strongest states (the USA was never a member, the USSR only from 1934-9), the absence of permanent meetings and the lack of any military force. When, during the next world war, further plans for another means to collective security were developed, the League’s weaknesses were a guide to what should be avoided. Plans for a new international institution with not dissimilar aims were discussed in Moscow in 1943 and by Roosevelt, Stalin and Churchill in Teheran (1943), and Yalta (1945). The form of what became the United Nations Organisation was agreed at Dumbarton Oaks (Washington DC) in 1944 and the UN Charter finalised in San Francisco in 1945 in which is stated:

We the peoples of the united nations determined … to practice tolerance and live together in peace with one another as good neighbours, and to unite our strength to maintain international peace and security, and to ensure, by the acceptance of principles and the institution of methods, that armed force shall not be used, save in the common interest …

With a Security Council in constant session at which the major powers had permanent places and whose decisions are binding on all members and the right to provide UN forces (not used until the Korean War, 1950-4), the UN had the potential to be a more effective means to collective security than the League. While the UN has been more involved with attempts to resolve international disputes than the League, such as Kashmir 1949, Suez 1956, the Congo 1960 and Cyprus 1964, in each of which UN forces were active, its provision of security has been weakened by divergent interests among the major powers, most markedly during the Cold War. Some argue that the mutually facing NATO (founded 1949) and the Warsaw Pact (founded 1955), and the balance of nuclear threat it provided, did more to preserve peace than the operation of the UN.

The termination of the USSR as a meaningful superpower, the invasion of Iraq in 2003 and the UN role to achieve security as world-wide terror, with its ideological connections with the Middle East, develops, signal new areas where the effectiveness of the UN as a means to collective security is untested.