The idea of a commonwealth founded on a shared national identity and established to protect regional security can be traced back to the Delian League of the 5th Century BCE, according to J.A.O. Larsen’s article “The Constitution and Original Purpose of the Delian League”. The Delian League, referenced in the writings of Thucydides, was a binding cooperative naval-based security apparatus formed as part of the larger Hellenic League. The Hellenic League prohibited all military conflict between member-states in order to foster a unified Greek front during the First Greco-Persian War.
The Delian constitution named Athens as the seat of the hellenotami, the governing seat of the Delian League, and established Delos as the seat of the treasury. Each member-state, qualified by their Greek citizenship, sent representatives to Delos to form an executive assembly in which they presented their vision for a unified Greek military policy. In theory, each state was to have an equal vote when determining Delian policy. However, as the hegemonia and commander of the Delian armed forces, Athens was able to coerce other smaller city-states to vote in its favour, thereby serving to undermine the founding principles of the League. While the Delian League proclaimed Greek freedom, it facilitated Greece’s imperial agenda and did nothing to ensure the freedom and right to self-determination of the ‘barbaric tribes’. In essence, the Delian League failed because it sought to create unity by force, rather than create unity through mutual understanding.
The Arab League was formed in March 1945 by Iraq, Syria, Lebanon, Transjordan, Saudi Arabia, and Egypt, as a reaction to the Ottoman decline, to settle regional disputes, and to govern issues common to a pan-Arab identity. The Alexandria Protocol of 1944, its founding document, called for a “loose confederation of independent states, which would have held periodic meetings to strengthen the relations between those states, and favoured political co-operation.” The Arab League is governed by a Council and a Permanent Secretariat, and a number of permanent committees. Ordinary council sessions are held twice a year, and its decisions are binding on voters. Decisions are not binding on non-voting Arab states however, which inhibits the efficacy of the vote.
Under the Pact of the Arab League of States, 1945, which serves as a reconfiguration of the Alexandria Protocol, member states are prohibited under Article 5 from using force against each other to settle regional disputes. The Council also has the right to determine the measures that should be taken in response to such measures, under Article 6, although the scope of such measures is not explicitly defined. The Arab League mediated in 19 of the 56 conflicts that took place within, and between, the Arab states from 1945 to 2008. According to Marco Pinfari of the London School of Economics, of the 19 conflicts, the Arab League failed to achieve success in 14 conflicts, including a failure to avert the 1948 Arab-Israeli War and the Lebanese Civil War. These failures are largely attributed to internal vetoes and the deferment of leadership to the UN and regional IGOs like the Organization of Arab Unity.
The British Commonwealth was founded to facilitate the decolonization of the British Empire by means of institutionalized economic assistance and international politico-economic cooperation and deliberation in the new post-war order. Article 1 of the Commonwealth Charter explains that the Commonwealth is neither a state nor a supranational entity. Yet, member states are obliged to adopt a coordinated security policy to deal with threats to their sovereignty, common security, and territorial integrity, with priority given to inter-ethnic and inter-confessional conflicts. This is outlined in Articles 11-12 and 16. Under Articles 18, 27, and 30, the Charter creates a governing body called “The Council of Heads of State”, which has the authority to recommend options for dispute settlement; a Council of Ministers to coordinate Foreign Affairs; and a Council of Defence Ministers, which coordinates the armed and peacekeeping forces of member states. Matters of coordinated economic policy are to be settled by the Economic Court, under Article 32.
The 1971 Commonwealth Heads of Government Meeting in Singapore established racial equality, liberty, democracy, decolonization and self-determination, economic equality, and a cooperative peace as the guiding principles of the British Commonwealth. In 1991, the Harare Declaration amended the original list to include the protection of human rights and the equality of all people regardless of race, gender, colour, creed, or political belief; empowerment through education; and sustainable development.
A modern Commonwealth defence pact would, necessarily, have to incorporate the principles espoused by the Delian and Arab Leagues, and the British Commonwealth. This would require a cooperative military alliance to protect threats to common security, a non-aggression pact between member states, and a legislative and juridical framework for dispute resolution between members and with external parties.