In late 1939, as Adolf Hitler's troops invaded Poland and World War II began, President Franklin Roosevelt received a two-page letter signed by Albert Einstein but mostly written by Leo Szilard, Edward Teller and Eugene Wigner. These physicists warned the president that Nazi Germany was working to make an atomic bomb and we should develop our own bomb before they did.

The president agreed and set in motion our own research program, code named the Manhattan Project.
On July 16, 1945, we detonated our first atomic bomb at White Sands, N.M. A month later, we dropped atomic bombs on Hiroshima and Nagasaki in Japan.

In the summer of 1946, I got off a troop ship in Yokohama to spend a year as a member of the U.S. Army in the occupation of Japan. After processing in Yokohama, I got on a train to go south to my new post at Fukuoka.

It was late afternoon as we passed through the train station at Hiroshima. I remember seeing part of the station had been rebuilt, but we were far from the center that received a direct hit of the atomic bomb so we had no radiation problems in the station at this distance.

There were a number of Japanese people standing on a platform waiting for a next train. When they saw our train filled with American troops, their faces showed nothing but extreme hatred. I was glad to be safely inside the train. I guess almost everybody who survived the bomb blast had lost relatives and friends in that explosion in Hiroshima.

That was the only time during my year in Japan that I felt threatened as an American.

Today, when I see TV reports from Afghanistan or Pakistan of natives who have had relatives killed by Americans, I think back to that train station in Hiroshima in 1946. It is not a good memory.

American military technology is the best in the world. However as we win battles on the ground, are we losing the battles for the hearts and minds of the people?

We are trying to harness the atomic power unleashed by the first explosion in the summer of 1945. In 1970 the Nuclear Non-Proliferation Treaty became effective on 5 March. Today, 189 states are parties to this treaty which was proposed by Ireland and Finland. Parties agree not to buy or sell information or materials which can be made into nuclear military weapons.

North Korea signed but later withdrew from this treaty. India, Israel and Pakistan did not sign and are not bound by non-proliferation treaty restrictions.

Iran and North Korea have programs working in the direction of obtaining nuclear weapons. Russia, China, Great Britain, France and the U.S. are the first states to possess nuclear weapons. Later, India and Pakistan both have nuclear weapons.

At the nuclear security summit held recently in Washington, President Barack Obama drew the world's attention to the problem of keeping nuclear weapons out of the hands of terrorists. I agree that it is one of the major threats facing all states in the world. However, I fear that since terrorists are groups of radical individuals, not states, they present a special difficulty at efforts to control.

The Cold War brought an effort to limit nuclear arms held by the Soviet Union and the United States. The Strategic Arms Limitation Treaty of 1968, known as SALT I, limited the number of missiles at 1,054 intercontinental ballistic missiles and 656 submarine-launched missiles for both countries.

This past April 8 in Prague, Obama and Russian President Dmitry Medvedev signed a new strategic arms reduction treaty. The START treaty limits the number of nuclear warheads for each country to 1,550. This is claimed to be a 30 percent reduction from the number of missiles in both countries.

I see it as something of about the same number of ICBMs and SLBMS permitted by the long expired SALT I agreement. I do not claim to be a military expert so maybe the new treaty really is a 30 percent reduction. I hope so.

If the number of nuclear weapons in the hands of state officials increases, there is a greater likelihood that a corresponding increase will develop for the possibility of terrorists to steal or buy nuclear bombs or components of bombs. Therefore the spread of nuclear weapons capability endangers the security of the entire world.

We must be careful, or our world might not continue to be.

Tom Nichols is a retired college professor who lives in Gainesville. His column appears regularly on Mondays and on gainesvilletimes.com.