Frederick the Great, having seized Silesia, left the task of justifying his conquest to his jurists. Some progress has been made since those unenlightened days. According to a detailed report published by the New York Times, the Kennedy team had legal consultants whose special assignment was to frame the "quarantine" edict (the ban on transporting so-called weapons to Cuba) in terms which would be as compatible as possible with principles of international law. This was advisable, the Times report adds, because the Russians are extremely sensitive to legal considerations.

Was this quarantine legal? A case can be made for it on the basis of precedent. In the past the technique of blockade - not confined only to offensive weapons - has upon occasion been used by one of the great powers to punish or reduce to submission a smaller power which has reneged on its debts or seized foreign enterprises. If such a blockade is not respected by the neutral nations, however, it may well result in acts of war. Was the United States legally entitled to invoke Paragraph 4, Article II of the United Nations Charter (prohibiting recourse to threats or to the use of force), and to accuse the Cuban Republic or the Soviet Union of having violated this Article? Even if we accept this premise, there is no article in the Charter authorizing a nation to be sole judge of which weapons in its opinion, constitute a "threat of force."

The truth is that the world we live in today differs fundamentally from the world envisaged by the framers of the Charter, and that the practical application of international law is only distantly related to the theory of international law.

The uneasy peace that reigns between the two great power blocs is founded on what is called a strategy of dissuasion; in other words, the permanent threat of the use of force. This military balance between the two blocs which the Charter did not foresee and to which Article 5 (the right of legitimate collective defense) lends a semblance of legality, is now accepted in Moscow and in Washington as permanent. To be sure, Mr. Khrushchev at regular intervals demands the evacuation of foreign military bases; but he is not surprised when, at equally regular intervals, Mr. Kennedy refuses to evacuate them. For Khrushchev himself demonstrated in Hungary that he would not tolerate the choosing of freedom by an East European nation which had been converted to Communism.

Beyond the Soviet zone proper, realism continues to prevail: Austria has been compelled to accept a kind of neutrality; Finland knows that her fate depends on Soviet good will rather than on American strength and she is pursuing a policy (at long last a happy one) of good neighborliness; and even Norway, which signed the North Atlantic Treaty, has refused to let foreign troops be stationed on her territory lest this "provoke" the Soviet Union. In other words, the smaller countries of Europe have learned through long experience that no great power will show any tolerance whatsoever toward a nation within the zone the former considers vital to its security, even if the latter has been officially recognized as a sovereign nation. The practical basis for America's action in the current crisis rests on this traditional and cynical prerogative of the major powers to impose limits on the action of the lesser powers. It is a right - or pseudo right - which no doubt antedated the United Nations Charter and which would have been invalidated by the Charter had the latter been applied. However, since peace today depends on the ability of each side to inflict massive reprisals on the other if the need arises, a concern for maintaining the balance should, in the interest of peace, take priority over our respect for formulae.

Outside the area where the two blocs conflict directly with one another, the expression of their rivalry is governed by a set of rules which is different but which is also alien to the spirit if not to the letter of the Charter. Subversion is a tolerated fact; the crossing of frontiers by troops of regulars is condemned. The organization and training of guerrilla troops to fight in the territory of a neighboring State was cited as an illustration in the definition of aggression drawn up by jurists between the two wars, and which even Soviet jurists retained in treaties signed by Moscow with neighboring countries (several of which have since ceased to exist). Nevertheless, for years Tunisia and Morocco allowed foreign troops to be stationed on their territory, these being at the time forces of the Provisional Government of the Algerian Republic which later became troops of the Algerian Republic. By contrast, even in the West public opinion was outraged by the French bombardment of Sakiet, although this bombardment was in reply to a violation of the law and was fairly easy to justify on legal grounds (which does not alter the fact that it was highly improper and ill-advised).

Will the Great Powers, particularly the United States, bow to the rule of non-use of regular troops in situations involving the allegiance of uncommitted nations? The American course of action in Cuba at least reveals the limits of this liberalism.

Although desiring to reduce the risk of war and the loss of life to a minimum, the US has made it clear that in the Western Hemisphere it will not hesitate, if necessary, to do what France and Great Britain were not authorized to do at Suez (and perhaps under the circumstances then prevailing, this prohibition was something of an expedient).

Certain uncommitted nations have been compelled by the Cuban crisis to recognize that they do not swing much weight in a showdown, and they harbor considerable bitterness as a result. Nevertheless, it would be a mistake if they failed to learn the obvious lesson. Realistic international law may grant lesser nations the right to choose their own form of government (though not to the extent of preventing the major powers from influencing this choice by subversion and counter-subversion); but it cannot grant these nations the right to acquire missile bases and to modify the balance of terror. At least for the time being, the United States will do its best to impose a radical distinction between the right to socialism and the right to thermonuclear weapons. Subversion is a legitimate tactic against socialism, but invasion is not. Where thermonuclear weapons are concerned, however, a quarantine and, as a last recourse, the use of force are legitimate.

During the Suez crisis, several of my American friends were carried away with enthusiasm because their President had placed considerations of international law above the ties of friendship. Should I now congratulate them because another President has, in the present crisis, placed their security above the law?