NOT LEARNING FROM HISTORY
It is impossible to discuss what mistakes Japan made in World War II without including some mention of how they ignored 2,500 years of naval tactics and paid a high price for doing so. The convoy system for protecting merchant ships goes back to when warships were first invented. When the Persian emperor Xerxes’ triremes lost the sea battle of Salamis, he was forced to withdraw most of his invading army from Greece. This was not because they were under any threat, but because his army needed to be supplied by merchant ships crossing the Adriatic Sea. With the loss of most of his triremes, Xerxes no longer had enough ships to convoy those merchants and protect them from Greek raiders. That, combined with a fear of losing his escape route across the Bosphorus, is why the Battle of Salamis won both the land and naval war for the Greek city-states.
In time of war during the age of sail, the practice of convoying groups of merchant ships with warships was the established policy for all of Europe. The English sea dogs always lay in wait for the Spanish plate (as in silver plate) fleet, which consisted of armed merchant vessels protected by Spanish warships. The English navy itself formed convoys during almost every war. A British convoy crossing the Atlantic during the Napoleonic Wars might contain as many as 100 merchants and be protected by as many as five frigates and often a ship of the line.
The British were slow to institute convoys in World War I, waiting until 1917. When they finally did, there was a nearly 50 percent drop in merchant ship losses. During that period, most of the coal used in France had to be transported to them across the English Channel. Initially, German submarines wreaked havoc with the slow cargo haulers. But once a strict convoy system was implemented, the total losses to submarines for the next year was a negligible four ships out of hundreds of sailings.
In World War II, the Royal Navy instituted a convoy, beginning on September 6, 1939. That convoy consisted of thirty-six ships sailing in four rows of nine each with an escorting warship front, right, and left. The first major assistance given to Britain, at Roosevelt’s insistence under the Lend-Lease Act, was not cannons or tanks, but fifty destroyers and fifty-four destroyer escorts. These were all used for the convoy duty of protecting Britain’s Atlantic shipping from U-boats. All British ships crossing the Atlantic during World War II were required to sail in convoy. After Pearl Harbor, a combination of the U.S. Navy instituting convoys in May 1942 and technical advances broke the U-boat offensive a few months later. By February 1943, with aircraft and even small aircraft carriers acting as escorts, the German navy lost forty-three U-boats and sunk only thirty-four merchant ships. Wellescorted convoys could overcome even the highly sophisticated tactics of Doenitz’s U-boats. Lone ships never had a chance. When Russia joined the war, convoys of weapons and ammunition were instituted to sail from Britain, past occupied Norway, to Murmansk.
Which leads to the question of why did Japan, the other major island nation engaged in World War II, fail to ever institute a convoy system? A large part of the reason may have been the attitude of those in command. Warships were meant to fight battles, not protect merchants. This strategy worked at first after the Philippines and Wake Island fell. Distances were too far for American submarines to spend much time in the major Japanese shipping lanes and subs were too few. But as the war progressed, the Japanese merchant fleet was subjected to ever greater losses with no reaction by the Imperial Japanese Navy other than to tell them to sail faster and zigzag. In December 1941, the Japanese lost only twelve merchant ships out of hundreds. In January, as the American bases in the western Pacific were lost, the number dropped to only seven ships lost. By that February, only two were sunk all month. Similar numbers prevailed until the end of 1943. This success without convoys meant dozens of destroyers could act as escorts to carriers, transport troops, or bombard enemy islands, and so the Japanese felt that their strategy worked.
But then losses began to mount, and rather than institute convoys, the Japanese reacted to the increased sinkings by announcing that more merchant ships had to be built. This “solution” was stunted by the limited shipbuilding facilities available and the competition for those same spaces by the Imperial Navy. By 1944, the Japanese merchant losses more than doubled, ranging from a low of sixteen to more than forty ships lost each month. Oil tankers particularly suffered. The amount of oil reaching Japan went from 1.75 million barrels in August 1943 to 360,000 barrels in July 1944. This was an intolerable level and far below the needs of either their industry or military. When the world’s largest battleship, the Yamato, made its final sailing, it had on board only enough fuel to reach the American fleet and not enough to get back to Japan. There was no more to spare for even the possibility that the great ship might survive to fight on. It didn’t.
Many in the U.S. Navy submarine service waited and even trained for dealing with Japanese convoys. They never had to. By November 1944, fifty-nine Japanese ships were sunk, mostly merchants or transports. By the end of the war, an amazing 54 percent of the total Japanese merchant capacity had been sunk. Most of the rest cowered in port. For a nation that totally depended on imported metals, oil, and even food, the fact they never instituted a simple policy that had been consistently successful for more than 2,000 years and had just proven amazingly successful for their opponents in the Atlantic is a mistake almost beyond understanding.
Japanese production and even the development of weapons was slowed dramatically by a continual lack of resources. The Imperial Air Force was crippled not only by a shortage of new aircraft due to a lack of metals, such as aluminum needed to build them, but also from an aviation fuel shortage so severe that pilot training was curtailed from weeks to a matter of hours. No matter what the bushido reasoning for the Japanese failure to institute convoys, the mistake allowed the American and Allied submarines to effectively destroy the very lifeline carrying the raw materials Japan needed to carry on the war. With more surviving merchant ships, the Japanese might well have slowed the American advance to the home islands and may even have negotiated something other than total surrender.