Statehood is an abstract construct of law and politics, both at the national and international levels. In modern international law the State is the stable legal organisation of a territorial political community in a form which enables it, along with other similarly organised communities, to form part of the international community of States.
States are the basic, primary components of the international community. As that community evolved two or three centuries ago it was, with only very rare exceptions of a sui generis character, composed exclusively of States. Today, with in particular the emergence of international organisations of many and varied kinds, it can no longer be said that the international community is composed exclusively of States, but they are still its dominant component.
It is, in particular, still only sovereign States which enjoy full international legal personality, i.e. the full range of legal rights, duties and powers which international law confers upon those entities which are subject to that system of law and the capacity to act on the international plane. But while sovereign States enjoy international personality in the fullest sense, they are not the only legal persons in international law. Other entities may possess international legal rights, duties and powers to a more or less limited extent and to that extent enjoy a limited degree of international legal personality: such is the case, for example, with international organisations, non-sovereign (e.g. protected) States, and entities with belligerent status.
While the modern State reflects the complexities of contemporary social and political structures, its origins owe much to the personal and feudal relationships between a ruler and his subjects (particularly the more powerful lords) owing allegiance to him. Their ownership or control of lands, when added to the ruler’s own lands, gave to his authority a territorial dimension within the boundaries of which the ruler exercised authority. At first the functions of central authority were limited to such basic matters as the defence of the realm, the maintenance of law and order, the making and enforcement of such laws as the ruler might make for the general benefit of his subjects, and the raising of taxes to pay for such relatively limited purposes.
Over time matters requiring the attention of the ruler and his court or immediate entourage grew in both complexity and extent, and relied increasingly on the approval of the populace. The organisation of the community became steadily more complex, which in time led rulers to associate a wider circle of powerful people with the task of governing their domains. In turn this established the beginnings of today’s widespread system of government through executive ministries each with its distinct functions, coupled with the association of popular representatives with the exercise of authority - a development accompanied in many cases by the gradual replacement of the religious underpinnings of the ruler’s supreme authority by more temporal attitudes to authority.
While the constitutional structures of the modern State can be traced back to origins many centuries ago, the essential core of the State has in practice remained firmly rooted in the territorial boundaries flowing from the personal allegiance which in early times linked ruler and ruled. The ‘people’ had a degree of homogeneity which served to identify them with their particular ruler and to distinguish them from the people under the sway of other rulers. In this homogeneity are to be found the seeds of modern notions of nationhood. But there are no sharp dividing lines in this area. Basic social units of families, villages and tribes probably owed more to the fellow members of those units than to the wider community of which they, through the prevailing hierarchies of allegiance, formed part. And at the territorial margins of a ruler’s authority, where his claims to authority abutted upon the claims of another adjacent ruler, neighbouring families, villages and tribes might well have had more in common with their fellows across the boundary than either would have had with the separate wider communities to which they formally belonged. In contrast, even within the territory subject to the ruler’s authority there will often have been groups feeling separate and alienated from the prevailing homogeneity of the territory’s other inhabitants.
Nevertheless, the proposition remains broadly true that the people subject to the authority of a ruler had a degree of homogeneity which supported their sense of belonging to that ruler’s community, and of not belonging to some other ruler’s community. This sense of belonging, constituting a prospective sense of nationhood, has always been of great importance to rulers and their emerging apparatuses of State, and they have always sought to develop the sense of nationhood in their populations. This they have done in various ways such as by the deployment of national flags and symbols, the adoption of national anthems, and the preservation of national languages.
Since the middle of the twentieth century, however, the sense of nationhood has in some instances been rendered somewhat more difficult by the explosion in population movements across the globe, whether as refugees from oppression and disease or as immigrants seeking new and better lives.
Current threats to the homogeneity of ‘nationhood’ and its role as the basic social cement for the political unity of the State come from both external and internal pressures. Until relatively recently international movements of people were on a very modest scale, but the present ease of international travel, coupled with human rights based restrictions on the return of immigrants to the countries from which they came, has led to influxes of numbers into some countries on such a scale as to dilute the ‘national’ characteristics of the existing population to such an extent, and at such speed, that, whatever the economic, cultural and other benefits of such population movements might be, the population’s sense of nationhood becomes more difficult to maintain. That difficulty in turn makes it more difficult in many cases to identify the essence of statehood.
The notion of statehood has been rendered more difficult not only by such influxes of people diluting the general homogeneity of the ‘people’ subject to a ruler’s authority and undermining the common allegiance owed by a ‘people’ to their ruler - the two bases for concepts of nationhood which underpin the modern State - but there are in many States people living within the State but with generally homogeneous racial, cultural and historical characteristics of their own, which are different from those of the ruler and the majority of the population. In short, they live under a ruler whom they regard as alien to their own roots. Such a departure from the normal homogeneity of ruler and ruled, reflecting a single nationhood, is likely sooner or later to lead to political instability and in particular to claims to self-determination. For the time being, however, such communities, despite whatever sense of alienation they may feel, continue to form part of the State which typically and for the most part represents that nationhood.
The term “nation State” is a commonplace of international relations, and reflects the origins and underpinnings of the institution which we now know as the modern State. But the State, as a legal entity of international law, is not dependent upon or coterminous with any such notion of nationhood. Although in many cases “State” and “nation” are in essence one and the same, this is a largely fortuitous outcome of the historical process.
States are the basic components of the international community, and it is therefore the law of that community - international law - which establishes the criteria of Statehood. The essence of Statehood reflects the needs of effectiveness. At its heart lie the factual requirements of a population and a territory, and the political requirement of an organized independent government.
The more detailed criteria against which the existence of States in international law is traditionally measured have been variously expressed, although the underlying theme is essentially the same. Thus Article 1 of the Pan-American Convention on the Rights and Duties of States 1933 provides that
“[t]he State as a person of international law should possess the following qualifications: (a) a permanent population; (b) a defined territory; (c) government; and (d) capacity to enter into relations with other States”.
A leading contemporary treatise on international law puts essentially the same thought in slightly different words:
“A state proper is in existence when a people is settled in a territory under its own sovereign government. There are therefore four conditions which must obtain for the existence of a state. There must, first, be a people... There must, second, be a territory in which the people is settled... There must, third, be a government... There must, fourth and last, be a sovereign government.”
In practice the various requirements that there be a government, that it be sovereign, and that the community has the capacity to enter into relations with other States are to a large degree all manifestations of a single overriding requirement of independence (despite difficulties which can arise in practice with its application), which is perhaps the defining characteristic of Statehood (of which, in particular, sovereignty is an attribute or incident rather than a condition for its existence).
In addition to the foregoing most commonly invoked criteria of Statehood other conditions are sometimes added (although they are in some respects already included within the foregoing principal criteria), such as a degree of permanence, a willingness to observe international obligations, a certain degree of civilization, the ability to function as a State and its existence as itself constituting a legal order.
It has been much debated whether the existence of a State is simply a question of fact (which is probably the predominant view), or whether some further legal act of recognition as a State by existing members of the international community is also needed. The question has become somewhat academic with the quasi-universality of the membership of the United Nations and the almost automatic entry into that organization of any newly established State, thereby showing the international community’s acceptance of the new entity as a State.
The four principal requirements for Statehood are not absolutes. Thus, while a State without a people is unknown, the population may in fact be quite small in number; a State’s territory similarly does not have to be large, and its limits (i.e. frontiers) may often be to a greater or lesser extent unsettled or even in dispute; the requirement that there be a government may at times be difficult to satisfy, for example in times of civil war; and the State’s sovereignty or independence does not always have to be full and complete, but may at times be attenuated by virtue of its relationships with other States. Nevertheless, such failures to meet the established criteria are usually both infrequent and only temporary, and for those reasons do not affect the entity’s existence as a State. Accordingly, those four criteria still sufficiently indicate the legal considerations against which a community’s existence as a State is to be tested.
It is notable that the requirement that a State must have a population does not include any suggestion that that population must, in relation to the State, evince qualities of nationhood. If it does, that is a bonus; but if it does not, the community will still be a State (so long, of course, as the other requirements are satisfied). Nor does the population, or even a major part of it, have to possess the attribute of the State’s nationality (the grant of which by the State is a matter for its own internal law, and is dependent upon the prior existence of the State as a State).
As a matter of social psychology, however, feelings of ‘belonging’ to a community, and in these days of the modern State of forming part of a nation which is institutionally constituted as a State, are very strong. Such feelings are not only positive feelings in favour of belonging to one’s own nation State, but also negative feelings of not wanting to belong to an alien nation State. But the fact remains that any coincidence of Statehood and nationhood is something of a bonus for the State, serving to strengthen the bonds which hold the State together. Even in the absence of any qualities of nationhood a community which fulfils the requirements of Statehood as indicated above will still be a State in contemplation of international law and, as such, be a legal person holding rights, duties and powers in international law, and a member of the international community.
Similarly devoid of any overtones of nationhood is the territorial component in the requirements of Statehood. A State is, in practice, defined by its territory. Its territory is that portion of the surface of the earth in respect of which, together with its adjacent territorial sea and its superjacent airspace, the State possesses sovereignty. This raises questions of law and fact but not of nationhood: a State’s territory does not, for example, have to be an area to which the population of the State feel bound by bonds of nationhood (although as with the population itself, if such bonds happen to exist, the State enjoys a bonus).
A State’s territory usually consists of an area surrounding the State’s central seat of authority, which will be its capital. That is the area in relation to which the State’s sovereignty is exercised, and in modern times (when there are no longer lands which are not subject to the sovereignty of any State -terra nullius) the limits of a State’s territory are the boundaries at which its sovereignty abuts the sovereign territory of neighbouring States.
The territorial scope of a State’s sovereignty is not, however, necessarily limited to the area surrounding the central seat of authority. Quite apart from States with off-shore islands, and the special situation of States which are composed of sometimes large numbers of islands located within the same general area (such as the Philippines, and Indonesia), historically many States have exercised sovereignty over territories which are not contiguous with the area surrounding their central seats of authority, and even in modern times a number of States still do so. Such a situation has come about as the result of the operation of the various rules of international law which at the relevant time provided for a State’s acquisition of new territories, such as purchase, conquest, occupation or cession. Territories acquired in such ways are often very distant from the State’s ‘core’ or ‘homeland’ territory (often referred to as its metropolitan territory). They nevertheless still fall within the State’s territorial sovereignty, and are as subject to its exclusive rights to exercise supreme authority as is its metropolitan territory. Accordingly, the concept of the State embraces all the territories subject to the State’s sovereignty, that is its metropolitan territory along with its overseas territories. It is for this reason, for example, that when a State concludes a treaty, as a general rule the treaty “is binding upon [it] in respect of its entire territory” (Vienna Convention on the Law of Treaties 1969, Article 29), including in that last phrase its territories in distant parts.
No particular States is necessarily a permanent and unchanging features of the international scene. The territorial limits of any given State may change over time as territory is lost or gained; it status as a sovereign State may change by being brought under the protection of another State; it may even disappear as a State altogether, as where it is absorbed into one or more other States. Similarly new States may emerge and become members of the international community, as where parts of an existing State break away and become separate States in their own right, or as where colonies gain independence from their parent State. The circumstances in which such changes may occur, and the consequences which follow, are the subject of various bodies of rules forming part of international law. Those rules, however, it should be noted, include two important elements: first, that even the extensive diminution of a State’s attributes do not normally affect the continued existence of the State itself, and second, that the distinction which is made between the State and its government enables a change in the government of a State to have no effect upon the existence of the State as a distinct entity.
 Oppenheim’s International Law, Vol. I (Peace), 9th ed. Jennings and Watts, 1992, pp. 120-122.
 See Brownlie, Principles of Public International Law (6th ed., 2003), pp. 75-76; Crawford, The Creation of States in International Law (2nd ed., 2006), pp. 89-95.