In the spring of 1942, there were three competing factions in Tokyo: The first, the Japanese Army, wanted to concentrate on the war with China. The second, Admiral Yamamoto and his coterie of naval commanders, wanted to concentrate on the destruction of the American Pacific Fleet, especially the aircraft carriers that escaped Pearl Harbor. And the third, the naval staff officers of the Imperial General Staff, wanted to continue the glorious conquests in the Pacific. The Imperial General Staff believed, not unreasonably, that the American carriers would eventually respond, and then subsequently be dealt with. Yamamoto disagreed, and felt they needed to be dealt with immediately. While the former two factions were busy actually fighting the war, the latter, the naval officers of the Imperial General Staff, like staff officers on overblown and bloated staffs anywhere far from any actual fighting (who have time for careerism, politicking, and pet projects) convinced the Japanese Emperor and Prime Minister Tojo to support further operations in the South and Southwest Pacific against the sage advice of Yamamoto.

The next offensive would be Operation MO – a complicated plan to seize New Guinea, the Eastern Solomon Islands, and eventually raid bases in eastern Australia and capture isolated American possessions in the South Pacific which would provide defense in depth for their main South Pacific naval base at Rabaul, and cut the direct sea lanes between Australia and the US. The attack had two parts. The first was a large naval task force with troop transports to seize Port Moresby on the southeast coast of New Guinea, which would effectively end all Australian resistance on the island. The second was a smaller naval task force to seize Tulagi, a small island off a then unknown larger island named Guadalcanal in the Solomon Island archipelago, as a staging base to seize Fiji, New Caledonia, and American Samoa.

These advances would be far from land based air cover and required a third part: the Kido Butai, Admiral Nagumo’s Carrier Strike Force, in order to prevent disruption by MacArthur’s bombers or Nimitz’ carriers. But the Doolittle Raid changed the dynamics of the faction politics in Tokyo. The Americans had done the unthinkable and struck at the heart of the Empire and threatened the Emperor himself. Yamamoto convinced the Emperor that the American carriers had to be destroyed lest they strike at Japan again (or inflict some other nasty surprise that the Japanese had not foreseen, but he didn’t say something so blasphemous to the Emperor). He had his operation against Midway approved and it became the priority for the Japanese Navy. But Operation MO was already in the final stages of preparation.

The Imperial General Staff, with their outsized influence, managed to get a compromise approved. The sticking point between the two operations was always the Kido Butai. Nagumo’s six carriers had reigned terror over one third of the globe for almost five months. But 24 hour combat operations took its toll. The crews were tired, and more importantly, no amount of Bushido or extolling from their officers could change the fact that the carriers and planes themselves were in desperate need of refit and maintenance. Yamamoto would need the Kido Butai at its peak proficiency to take on Nimitz’ carriers in their own waters. The Imperial General Staff recommended that the “A team” of the Kido Butai, the 1st and 2nd Carrier Divisions consisting of the big fleet carriers Akagi, Kaga, Soryu, and Hiryu return to Japan to refit for the Midway operation, while the “B team”, the 4th and 5th Carriers Divisions consisting of the light carrier Shoho and more modern fleet carriers Shokaku and Zuihkaku sail south to take part in Operation MO in the Coral Sea. The rivalry between the carrier divisions offers a unique insight into the Japanese mentality of the time. Though the light carriers and the Shokaku and Zuihkaku were more modern, they were newer and therefore younger and deserving of less respect than their elders. The best pilots and crew went to the older carriers which were referred to as “the sons of the wives” while the newer ships were referred to as “sons of the concubines”. This also meant that the crews and pilots of the newer ships had to work harder to gain face. So in that light, the General Staff was doing them a favor by letting them participate in MO and then immediately move north to take part in the Midway operation without respite. Of course all of the carriers and their pilots wanted to do this, but Yamamoto understood there was a limit to the military efficacy of honor and determination in modern naval warfare. He wouldn’t permit more than two fleet carriers skip the desperately needed maintenance and refit. The end result was that for the first time in the War in the Pacific, the Kido Butai, the mailed fist of the Japanese Navy, was split into its component parts.

This was exactly what the Americans needed to happen. With Halsey, and the Enterprise and Hornet still returning from the Doolittle Raid, Nimitz only had two carriers left, the Yorktown and the Lexington. (The Saratoga was in drydock after being torpedoed, and the Wasp was delivering fighters to Malta at the ardent behest of Churchill). Unfortunately for the Japanese, American and British codebreakers knew of the Japanese plan and Operation MO was at the tail end of a long supply chain back to the Home Islands. For the first time in the war, the Allies would be able to engage the Japanese fleet with near parity in resources.

American aircraft carriers Yorktown and Lexington under Rear Admiral Frank Fletcher were dispatched to the area. On the morning of 3 May 1942, the Japanese landed on the island of Tulagi and the next day aircraft from the Yorktown savaged the eastern Japanese task force. But the Japanese carriers weren’t there. In fact it was the smallest and least important of the five Japanese task forces lurking nearby. Ship identification was the biggest culprit, and the pilots reported 14 cruisers, destroyers and transport ships sunk, when the actual toll was just a destroyer, a few small gunships, and a freighter. Even worse, this action alerted the Japanese to the presence of the American carriers in the area and the Japanese fleet carriers entered the Coral Sea with the purpose of finding and destroying the targets they missed at Pearl Harbor. For the next two days, air patrols from ADM Fletcher’s aircraft carriers searched the Coral Sea for what he believed to be four Japanese carriers supporting the Port Moresby invasion force and the Japanese did the same for what they thought were two more American carriers in the area.

However, neither side had ever faced their adversary’s carriers with their own carriers before. And the limitations of air reconnaissance, radio communications, and sea navigation over great distances against fast moving fleets with their own inherent air cover in variable weather were keenly felt by both sides. Furthermore, each side approached from an unexpected direction: the Japanese from east around the southern tip of the Solomons and not north from Rabaul, and the Americans from the south instead of the east.

For the next few days, both sides flailed about like blindfolded boxers listening to sighting reports from their trainers in the corner. First, the Americans spotted the invasion force but reported it as the striking force with the fleet carriers and launched their full complement of aircraft against the wrong target. Fletcher was livid with the scout when he returned to confirm no carriers but when confronted with his report realized he transmitted the wrong code. Fortunately for the scout, a carrier was spotted nearby but it was only the light carrier Shoho with the invasion’s covering force. The massive strike put eleven torpedoes and six 1000 lb bombs into the poor Shoho, but it was mostly wasted effort as the strike still left the Yorktown and Lexington vulnerable to the Shokaku and Zuikaku prowling nearby. But the Japanese had their own problems with identification: the next day they spotted and sank an oiler and destroyer that Fletcher dispatched away from the fleet to keep them safe, which was reported (and eventually showed up in Japanese newspapers) as an aircraft carrier, a cruiser, and one American and one British battleship sunk. The attack actually flew over Fletcher and his carriers who were obscured by low clouds. On the return trip, the Japanese spotted them, and launched a limited late afternoon attack with their most experienced pilots in which they couldn’t find the Americans. That night they all got lost and ditched. Nine of them even mistook the American carriers for their own and tried to land. The Japanese lost more pilots to the sea in one evening than they had to American guns so far in the war.

That night the two task forces passed within 70 miles of each other in search of their respective foes going opposite directions.

But both sides knew each was close by. The 8th of May would be decisive. The victor would be the one to strike first. But that was not to be the case. On that morning, they both struck simultaneously. Fletcher spotted and heavily damaged the fleet carrier Shokaku, but missed the Zuihkaku in a rain squall just 12 miles away. At almost the same time, the Japanese struck the Lexington and so severely damaged the Yorktown they believed she was sunk. The crew of the Lexington thought they had her damage under control, but leaking fuel fumes ignited when they reached the engine compartments. Over the next six hours, the Lady Lex was wracked by increasingly worse explosions as uncontrollable fires slowly engulfed the beloved ship. She was abandoned that evening. Both sides took heavy aircraft losses but repair crews managed to keep the Yorktown afloat and whatever American planes were left in the air were able to land. The same was not true for the smaller Zuihkaku; Japanese crews had to push aircraft off the deck in order to make room for the Shokaku’s planes. The Americans might have lost more tonnage in ships in the battle, but the Japanese lost many more aircraft, most by their own hand.

With only one wounded carrier remaining, Nimitz ordered Fletcher to withdraw from battle and head for Pearl Harbor for repairs. Both admirals believed there were still three Japanese carriers about (there was only one, the Zuiakaku), and without any way to refuel, the Yorktown would have to severely curtail her ability to maneuver. Fortunately for the Americans, the Japanese commander, ADM Inoue at faraway Rabaul, had taken such heavy losses in aircraft he did not believe he could take Port Moresby without air cover and also withdrew, defaulting victory to the Allies.

For the first time since America entered the war, the Japanese had been stopped. Australia was saved from invasion or eventual death by strangulation. Additionally, the Shokaku and Zuihkaku would be unavailable for the upcoming operations against the American carriers around Midway. The Battle of the Coral Sea was the first naval battle in history in which the opposing ships never actually sighted each other or exchanged direct fire. It would not be the last.