The following are excerpts from President Conant's foreign policy speech, delivered yesterday in Chicago.

It is only a question of time before we will be living in an age when the possibility of the destruction of many vital centers from the air (by atomic bomb) is a danger common to both the Soviet Union and ourselves. . .

If a global war can be avoided and Western Europe made secure against invasion from the east, then in the course of years negotiations with the Soviet Union could begin to take a realistic turn.

On the other hand, if by subversion or aggression Communism should reach the Channel ports, a global war would seem inevitable unless the United States were prepared to bow before the might of the whole Eurasian continent under Soviet rule.

Thanks to the Marshall Plan the danger of Communist control of France and the Low Countries through revolution seems now remote. Against direct military aggression the same countries are now defended by the striking power of the United States Strategic Air Force armed with the atomic bomb. This deterrent power I believe to be very great.

A Balance of Two Threats

If Russian troops should start to overrun Western Europe tomorrow, I believe the Russian industrial centers would be destroyed from the air. Thus at this moment there is a balance in the West between the Communist would and the free nations. But it is a balance of two threats--no true balance of equal forces. . .

As long as this sort of balance obtains, no basis for any real negotiation can possibly exist. We cannot forego the potential use of the atomic bomb, frightful as such use might be, as long as there is no way of stopping the movement of Russian troops by adequate ground defenses. . .

I am well aware that opinions have been expressed with great frequency and violence that the defense of Europe by ground forces is impossible . . . As to the latter (military considerations) I should like to remind you . . . that Dr. Vannevar Bush, who has considerable knowledge of modern weapons, believes that the technological advances of recent years enormously favor the defense of land positions against mechanized and armored troops.

Atomic Support on the Ground?

He points out that at a not too far distant date even the use of atomic weapons for the support of ground forces may be a possibility for the United States . . .

And I venture the prediction that these technological changes will make it possible for armies based on the manpower of the present Atlantic Treaty nations to face Russia and its satellites on equal terms without calling on Germany to rearm . . .

At all events we are not even now in a position where we must match man for man, where we must mobilize an army equal in size to the Russian hordes . . .

In the so-called great debate which is now in progress little has been said that can give comfort to those who once advocated a purely hemispheric stand against Communist aggression, nothing that would support a smaller armed force than three or four million men . . .

There can be no real issue as between concern with the military situation in the Far East and concern with the rapid building of the defense of Europe.

United Action Essential

United action by three nations--the United States, Great Britain and France--is essential to the defense of Europe . . . But each of these nations is involved in military and diplomatic problems in Asia which are to some degree peculiar to each country . . .

Many of us who disagree strongly with the policy advocated by General MacArthur do so not because we attempt to pass judgment on the military risks involved--these are matters it seems to me that must be left to responsible military authorities, but because it would appear that General MacArthur is prepared to have the United States go it alone in the Far East.

But to follow such a course of action would make impossible the unity required in the extremely difficult matter of rearming Europe . . . If the free world is to remain free and secure, it must be united . . .