In brief, the world seemed to be back in that state of international anarchy, in which power alone counted, from which it was to have been rescued by collective security. To sum up the analysis, collective security failed to find a compromise between national and world sovereignty because sovereignty is inherently indivisible. In the last analysis, sovereign states cannot be fully bound by pledges to act in some hypothetical future case, especially where such pledges involve the risk of war. Plans for collective security demand such ironclad commitments, or the system decays into just another instrument of national policy (as the United Nations has tended to become). United Nations actions do not supersede politics among nations; they become a branch of these politics. The United Nations only mirrors the existing international society. National sovereignties remain the basis of world politics, and in the last analysis these sovereignties will agree to cooperate only so far as that serves their interests. Such cooperation may indeed accord with their interests at times, but there is no assurance that it will. The larger powers (who, after all, must bear the major burdens of enforcing peace under a collective security system) have never been willing to give an unconditional commitment to carry out the commands of the world organization; they have always reserved for themselves some escape hatch. They have never been willing to set up an international army of any significant strength, under direct control of the League of Nations or the United Nations without strings attached. This is to say that it still is a world of nationalism and national states. If a world superstate could somehow be set up, this would obviate and supersede collective security, which in theory is a hypothetical stage somewhere in between. In the terminology of the German sociologist Karl Mannheim, collective security is a "relative utopia"—one that tries to be realistic but retains elements of fantasy.
An army under the direct control of the international organization, one that could be used without asking permission of the various member states, seems necessary to collective security; otherwise, as has been the case, it must make ad hoc requests for military contingents, which the various governments may or may not choose to honor, depending on their interests. If it had its own army, the United Nations would already be a world government, possessing sovereign powers over the subordinate member units.
One of the illusions of collective security, as was observed, seems to be that conflict is relatively rare, is a product of criminality, and can readily be recognized as "aggression" and as such suppressed by the great majority of law-abiding, peace-loving peoples. But conflict is both much more endemic in the world and much less possible to categorize as good and evil than this theory concedes. Aggression has proved much more difficult to identify and to define than collective security plans foresaw. In such clashes as those between Israel and the Arab states, North and South Vietnam, North and South Korea, India and Pakistan, and perhaps most others, there is great difficulty in ascertaining who in fact struck the first blow, as well as a certain aridity in making this the crux of the matter. Does aggression include indirect attacks such as subversion and propaganda? How far back in time should one carry the feud? What states were ever at war and did not each charge the other with the aggression? Historians still debate the responsibility for World War I and most other wars. In this respect, Hitler's unashamed Realpolitik from 1936 to 1941 was a rarity in the history of wars.
Although some have argued that any "breach of the peace" ought to be a signal for a "police action" by the world organization, regardless of who is responsible, or have suggested formal tests such as willingness to submit the dispute to an arbitrator or mediator, in fact the validity of the theory seems to depend on clear criteria of aggression. But attempts to reach a satisfactory definition of aggression failed in long years of debate, first in the League of Nations and then in the United Nations. Some argued that a definition is undesirable, because it could not cover all the contingencies and would be "a signpost for the guilty and a trap for the innocent." States might find themselves in the position of having to act against a friend or defend a foe. The reality of international relations in a world of particular sovereignties thus again confuses and thwarts the ideal of a pure collective security system. (After twenty-four years of effort, the United Nations Special Committee in 1974 did finally agree on a tortuous definition of aggression, but one too full of exceptions to be very helpful.)
There is also the argument of redundancy. A workable collective security order is one in which most of the powers are in harmony, and which has enough unity to agree on basic definitions, for example, of justice and aggression. It is significant that the idea has come into play in state systems marked by considerable underlying cultural unity, as in ancient China or modern Europe. But if there is this much unity, there is hardly any need to install a system of collective security, for the problem will virtually solve itself. To create the formal institution of a League of Nations or United Nations does not alter the existing order of power and international relations.
Insofar as collective security is based on a firm defense of existing borders, it is open to criticism on the ground that this freezes the status quo. This raises the problem of justice. Many states will not accept the justice of existing boundaries, which probably reflect the results of recent war and may contain arrangements clearly unacceptable to the losers. Many groups fervently advance claims for the revision of frontiers at all times, as, for example, at the beginning of the twenty-first century with the Arabs and Pakistanis. Collective security thus was in danger of being labeled the selfish policy of satiated or victor states. (Germany consistently viewed it in that light between the world wars.) One must allow for some method of revising existing boundaries or one has condemned a dynamic world to immobility, which clearly is impossible. Proponents of collective security may urge "peaceful change," but how is this to come about? Their theory contains no specific answer. In a world without a single government possessing laws and courts that are binding on and acceptable to all, war must remain a possible last-resort remedy for injustice. Here we impinge upon arguments against pure pacifism and confront again the nonexistence of world government. It may be noted that support for wars of revolution and "liberation" runs counter to collective security's immobilism. Those who believe that there is indeed a "just war" for national independence, recovery of a region forcibly seized in the past by another state, overthrow of an oppressive government, or some other such compelling cause will defend the right to resort to it rather than submit indefinitely to an unjust peace. (In the late 1960s and early 1970s the United Nations General Assembly, with a Third World majority, voted that nations should wage war on the "racist" government of Rhodesia, not for violating any frontier, but for being unjust.)
Insofar as it is based on guaranteeing frontiers, collective security assumes not only that these frontiers are just but also that they are well-defined. Collective security was more suited to the classical European state system than to much of the world today, where boundaries are ill defined or even nonexistent, and where civil wars, wars of secession, and wars of "liberation"—sometimes with outside aid—are the most usual types of violent conflict.
Finally, the basic dilemma of collective security is—assuming its efficacy—that of waging of war to prevent war. War by any other name, including "police action," is still war. Of course, the advocates of collective security hoped that vigilant international police work performed in time would nip a potential war in the bud—stamp out the brush fire before it became a raging inferno. But experiences such as Vietnam suggest that well-intentioned interventions of this sort may result not in diminishing war but intensifying it. Intervention by outside powers, even if acting in the name of an international organization, is, after all, not usually apt to reduce a conflict. In principle, collective security abolishes neutrality; no state may stand aside and observe, all must become involved to stop a war. (The 1930s saw a considerable debate on the implications of the new doctrine for traditional neutrality.) But the venerable principle of neutrality may be valuable in confining the scope of a war. To abandon it may involve the risk of widening wars.
In this connection, "limited war" theorists and strategists advise accepting the inevitability of war while seeking to keep it as confined and limited as possible, rather than trying vainly to abolish it. Collective security has been accused of unrealistically demanding the total suppression of war, and in its anxiety to achieve that goal, blowing up every skirmish into an international crisis.
The criticisms have called seriously into question the workability of collective security, perhaps the chief idea of the twentieth century addressed to the problem of war. It was born of the shock of 1914 and nourished by the further horror of World War II. Its goal was to bring an end to the "international anarchy" of blindly competing states, acknowledging no limitations on their powers except those of brute force. Recognizing the existence of nationalism as a powerful fact not likely soon to be extinguished, followers of collective security conceded to realism that dreams of a world state are as yet wholly premature; they tried to build on the foundation of independent sovereignties a society or league of nations to which these sovereign powers would offer their voluntary cooperation, in the common interest of suppressing war. In the last analysis such a compromise between national and international sovereignty seems impossible—the gulf is unbridgeable. Those who are unprepared to accept continuing prospects of rivalry between nations and peoples, mitigated only by diplomacy and leading intermittently to war, must face the formidable task of creating a world community able to support a world government.