High above the lagoon, Colonel Richard Leghorn piloted his airplane through the bright blue sky. To the south, in the distance, cumulus clouds formed. The U.S. Army Air Forces navigators had sent Leghorn close enough to ground zero to assess what had happened down below on the lagoon, but far enough away so as not to be irradiated by the mushroom cloud. What Leghorn witnessed horrified him. He watched Baker’s underwater fireball produce a hollow column, or chimney, of radioactive water six thousand feet tall, two thousand feet wide, and with walls three hundred feet thick. The warships below were tossed up into the air like bathtub toys. The Japanese battleship Nagato, formerly the flagship of Admiral Isoroku Yamamoto, the man responsible for planning the attack on Pearl Harbor, was thrown four hundred yards. The retired USS Arkansas, all twenty-seven thousand tons of it, was upended against the water column on its nose. Eight mighty battleships disappeared in the nuclear inferno. Had the armada floating in the lagoon been crewed to capacity, thirty-five thousand sailors would have been vaporized.
From up in the air Colonel Leghorn considered what he was witnessing in the exact moment that the bomb went off. It was not as if Leghorn were a stranger to the violence of war. He had flown more than eighty reconnaissance missions over enemy-controlled territory in Europe, from 1943 to 1945. On D-day, at Normandy, Leghorn made three individual passes over the beachheads in a single-seat airplane without any guns. But like O’Donnell, Leghorn was able to recollect Operation Crossroads with precise detail after more than sixty years. For Colonel Leghorn, this is because he remembered exactly how it made him feel. “I knew in that life-defining moment the world could not ever afford to have a nuclear war,” Leghorn says. The only sane path to military superiority in an atomic age was to spy on the enemy so that you always had more information about the enemy than the enemy had about you. Leghorn says, “That was the way to prevent war and that is how I formulated the original idea of overhead.”
At the time, in 1946, America’s intelligence services had virtually no idea about what was going on in Russia west of the Volga River and absolutely no idea what was happening west of the Ural Mountains. Leghorn believed that if the United States could fly secret reconnaissance missions over Russia’s enormous landmass and photograph its military installations, the nation could stay ahead of the Russians. By spying on the enemy, America could learn what atomic capabilities the Russians had, what plutonium-or uranium-processing facilities existed, what shipyards or missile-launch facilities the Soviets were constructing. And because Leghorn was a scientist, he could imagine precisely the way the military could accomplish this. His idea was to create a state-of-the-art spy plane that could fly higher than the enemy’s fighter jets could climb or than their antiaircraft missiles could travel. In that moment during Operation Crossroads, Leghorn committed himself to developing this new philosophy of spying on the enemy from above, a concept that would come to be known as overhead, or aerial, espionage. Leghorn’s efforts would take him from the halls of Congress to the corridors of the U.S. Air Force Strategic Air Command. There, he would be at odds with a third set of eyes watching the twenty-three-kiloton Baker bomb at Crossroads. The eyes of Curtis LeMay.
LeMay’s perspective could not have been more diametrically opposed to Leghorn’s spy plane idea. LeMay believed that atomic bombs, not conventional explosives, won wars. Japan did not surrender after the firebombing of Tokyo. The empire surrendered only after America dropped its second nuclear bomb. During the atomic tests at Bikini, LeMay knew what only a few others knew, and that was that the Joint Chiefs of Staff had recently reversed America’s long-standing national policy of only going to war if attacked first. The JCS’s new and top secret first-strike policy, code-named Pincher, now allowed the American military to “strike a first blow if necessary.” A single effort could include as many as thirty atomic bombs dropped at once. The new and unprecedented policy had begun as a planning document less than one month after the Japanese surrendered, on August 15, 1945. Ten months later, on June 18, 1946, the policy legally took effect. No doubt this influenced LeMay’s perspective at Crossroads.