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Originally published in Tuttoscienze of LA STAMPA 16 June 2004

In the late ‘70s, the world was shocked by a controversy regarding the neutron bomb, a nuclear weapon invented by American physicist Sam Cohen and which was nicknamed “the capitalist bomb,” as it was able to kill living beings while minimising damage to “property” - that is, buildings.

The father of the neutron bomb has just published an online version of his autobiography (see www.athenalab.com/neutrons7-t.pdf) which strikes a chord because of its sincerity – indeed brutal sometimes - because it is full of disputable opinions, irreverent comments and names and surnames. We asked Sam Cohen to tell us his story.

How did you get involved in nuclear weapons research?

I had obtained a degree in physics at the University of California, Los Angeles, and I was in the Army during the Second World War. I was told to pack and I was sent to Los Alamos.

How and when did you arrive there?

Early in 1944. I was 23 and I had never heard of the Los Alamos lab. As soon as I arrived at the railway station in a neighbourhood near Santa Fé, other soldiers and I were picked up by a truck. We had received instructions not to ask anyone about where we were going and why. As soon as we arrived at a gate full of guards, we were brought to the barracks and told we could not leave there. We could visit the library, though, which was also open to people like us who had no special authorisation. The day before I went to the library, I noticed quite an unusual thing: in a remote place such as it was, I saw three Nobel Prize winners in nuclear physics, and so I began to suspect that there in Los Alamos something relating to military applications of the atom was going on. But I could not imagine what was going on. But then I went to the library, where I found many articles concerning nuclear fission. And so my suspicion began to mount and when I was called to have an interview with Dr. Weisskopf, he asked me: “what do you think we’re doing here?”, I replied, “I think you’re building an atomic bomb.”

I suppose you shocked him, as that was absolutely secret.

Yes, Weisskopf blanched. I told him that I had read the articles in the library. One week later, those articles were removed from the library and taken to that part of the library where only cleared people had access. Once I understood where I had ended up, I was really excited as I realised that it was a historical enterprise.

What exactly did you do at Los Alamos?

I was posted in the theoretical division headed by Hans Bethe and we studied how neutrons behave: how they scatter around, how they are absorbed and provoke nuclear fission and chain reactions. I developed a special relationship with them and so, many years later, I developed the neutron bomb.

What happened at Los Alamos at soon as the Hiroshima bombing was announced?

That evening, Oppenheimer made a triumphant entry and everybody –with the exception of maybe one or two people- rose, cheering and stomping. Everybody was very proud that what they had built had worked properly. Oppenheimer quieted the theatre down and said that, at that moment, little was known about the bombing; all they knew was that the Japanese had not liked it and that, in any case, he was deeply regretful about not having finished the bomb in time to use it against the Nazis. Once again, elation broke out. And it didn’t pass through most minds that that lab has just killed 100,000 innocent civilians.

And how did you react?

Like the others. I had not forgotten Pearl Harbor and how we had gone into the war. And during the war I was never bothered when the Japanese were firebombed, I didn’t have moral scruples. But looking back, I think I should have had them, and now I am a different person. I believe in the Christian just-war principle.

Are you Christian?

No, I’m an atheist. Ethnically, I am Jewish.

Did you work on the bomb because of the Nazis?

I worked on it because it was one of the greatest scientific revolutions and it was absolutely exciting.

Immediately after the end of the war, you went to work at RAND Corporation, one of the world’s most famous think-tanks. What did you do there?

I worked on various kinds of nuclear weapons, and it was on the basis of this work that, in 1958, I invented the neutron bomb.

However, you were kicked out of RAND in 1969...

I've been kicked out by everybody!

How did it happen?

I became a rebel and wrote against the nuclear policy of the government, but the government was paying RAND, which was paying me; they cut off my salary. I was forced to go into early retirement, but my wife and I were able to pay the mortgage for our beautiful house and we raised our family.

In your opinion, what was the American government’s worst mistake, in terms of national security?

According to the government, it wasn’t possible to use nuclear weapons, not even to defend Western Europe from an attack. I thought this policy was totally wrong, dangerous and irrational, but this anti-nuclear attitude went on for years and years, and I don’t see any sign of change.

Do you not think that maybe the government was right in its “anti-nuclear views”?

The government was wrong! Let’s go back in history: during the Vietnam war, the Secretary of Defence released an official statement in which he stated that no nuclear weapons would have been used, no matter what the conditions. But if we had used my neutron bomb, we could have won the war; many American and Vietnamese lives coud have been spared, and hundreds of billions of dollars would have been saved as well, and that money could have been used for education and medicare purposes. The decision not to use the bomb was immoral. And the same statement was made by Bush during the first gulf War: no nuclear weapons, regardless.

Let’s speak about your neutron bomb...

It is a nuclear weapon less powerful than the one launched on Hiroshima which was an atomic bomb and, of course, less powerful than the hydrogen bomb, or H-bomb. It releases high energy neutrons which kill living beings and spare buildings. The neutron bomb is a battlefield weapon and it is intended for discriminate use against enemy troops and not for attacking cities, unlike the atom and the hydrogen bomb, which devastate and contaminate enormous portions of the enemy country’s territory and kill hundreds of thousands of people, if not millions.

However, you also helped in the building of the hydrogen bomb...

Yes, but that bomb was a trap, because how much damage do you want to do to an enemy country? Teller, who was a strong anti-communist, was convinced that there were no limits to the damage you could do to the Soviet Union, you could blow up the entire nation. I disagree, and for this reason I believe that the neutron bomb is a moral weapon: very discriminative and in accordance with the Christian just-war principle. And this was appreciated and recognised by the Vatican: in 1978, Paul VI gave me the Peace Medal.

Why did you invent that bomb?

I didn’t invent it to use it against the Soviet Union, rather I invented it for “limited wars” like the Korean and Vietnam wars. And I invented it because I firmly believe in the just-war principle, which discriminates between soldiers and civilians. But there were demonstrations all around the world against my bomb.

Even Teller didn’t appreciate it!

Because he hadn't invented it! He was a megalomaniac.

And Brezhnev called you “monster.”

Yes, and then the neutron bomb became the number one priority in the Soviet Union! They could even have thousands of neutrons bombs. And we Americans helped China have its neutron bomb.


That was realpolitik: we helped the Chinese achieve the neutron bomb in order to defend themselves in case there had been a war between China and Russia.

You have persistently recommended using your bomb in wars such as the Korean and Vietnam wars. Aren’t you scared that using a nuclear weapon, no matter how small, it could go from being a limited and conventional war to a nuclear war?

I recommended using as discriminative and effective weapons as possible in order to win those wars as humanely as possible. The fact that China or Russia could go into war with their nuclear weapons is a conjecture.

Today, the problem of the development of small nuclear weapons to be used in combat, rather than to be kept in arsenals as a deterrent, is very timely. George W. Bush wants the so-called bunker busters, nuclear weapons whose power is relatively small, to be used against bunkers. However, authoritative supporters of nuclear disarmament fear that nuclear weapons –which haven't been used since Nagasaki - be cleared...

The idea that small and usable nuclear weapons could legitimise other nuclear weapons and lead to nuclear war is nothing other than a theorisation, which doesn’t have any legitimate basis.

And so why, in your opinion, is there such a strong prejudice against nuclear weapons, even in the American government?

It is due both to the establishment’s economic interests – if we adopted a sensible nuclear policy, we could reduce the defence budget, which is now in the order of 400 billion, by 100 to 200 billion dollars per year- and it is also something primordial and irrational: in the world there are good guys, bad guys and nuclear arms supporters, who are the worst.

However, even a president like Reagan said: “a nuclear war cannot be won and should not be fought”.

I met Reagan in 1978 and we spoke about the neutron bomb. He strongly inferred that if he were elected he would restart the neutron bomb production which Carter had blocked. And he did. However, a coherent strategy for using the bomb was never developed and so it cost close to 1 billion dollars, but it was useless. Reagan’s national security campaign advisor promised me an award for having invented it. I am still waiting for that award!

In conclusion, throughout your life you have experienced several disappointments: do you feel yourself to be a loser?

I have had a long life. After I was forced into early retirement, I began writing because that was all I could do. Next January, I’ll be 83. Life has offered me fascinating opportunities and I have no regrets, but sometimes I am a bit sad.