This chapter examines collective self-defence treaty arrangements. It engages with a diverse range of examples of the collective self-defence treaties (or treaties that contain collective self-defence aspects) that have emerged since 1945 to draw out common themes as to the nature, process, and role of such arrangements, as well as to establish notable variations. The aim is to contribute an overall picture of collective self-defence today specifically in the context of treaty relationships. The chapter argues that such relationships inevitably impose only weak obligations on their parties to defend each other and also can cause notable issues related to overlapping memberships, bureaucracy, and antagonism amongst members (amongst other difficulties). Equally, these arrangements – of which there are now hundreds – are concluded for good reason(s). They provide a range of benefits, especially in terms of their deterrent effect.

The idea of the Free World emerged in World War II from the struggle of Western liberal democracies against their autocratic and totalitarian enemies. After the war, the Free World consisted of the United States, a group of Western European liberal democracies that re-emerged after liberation from Germany and sought American protection, and the reconstructed and mostly demilitarized war enemies Italy, (West) Germany, and Japan. The US-led anti-communist alliance building in the wake of the Korean War increasingly included Asian and the Middle Eastern countries in the defense of the Free World, although they often were authoritarian . The liberal-democratic nature of the Free World’s core in Europe allowed open political disagreements to emerge, mostly between Charles de Gaulle’s France and the Anglo-American powers but also within the societies of the Free World itself. These conflicts reached their combined peak in 1968 over the Vietnam War and widespread popular protests in several Western countries. The Soviet intervention in Czechoslovakia and subsequent changes of government in the West, however, helped to recreate a semblance of unity within the Free World by the early 1970s.

In his 1995 treatise Fairness in International Law and Institutions, Thomas Franck described what he called the ‘reality-altering’ potential of the UN Charter’s system of collective security in these words.

I argue that the (often idiosyncratic) interventions of Pakistan’s diplomats and international lawyers in Kashmir, Jammu and Pashtunistan, as well as in Bandung and Havana, form a distinct legal and political trajectory, which is at odds with the arbitrary, yet ubiquitous, conceptual delineations between ‘cold’ and ‘warm’ wars. Far from being peripheral to global Cold War developments, Pakistan’s internal and international relations and troubles provide a rich source of strategies and ideas about the state, law and society in the Third World. They are, however, also a testament to the centrality of class struggle in a post-colony – a struggle, exemplified in the events of 1951, that no lawfare could bring to an end.