Imperial Japans fortunes turned sour in 1944. To try and turn the tables, Operation Ichi-Go, or Operation Number One, came into being. Launched in China in April 1944, Operation Ichi-Go was Imperial Japans biggest offensive in World War II. It aimed to reinforce Japans position in China in the face of American incursions into the region. In Japanese, the operation was also known as the Continent Cross-Through Operation, as one of its main goals was to secure an overland rail route through French Indochina and China to transport raw materials, as well as neutralize US bomber command bases in China.While the Japanese were successful in most of their offensives, why was the operation itself a failure overall?The Sino-Japanese WarJapanese troops enter Manchuria at the start of the Sino-Japanese War, c. 1931-1932. Source: Wikimedia CommonsJapans difficult war with Nationalist China predated World War II, starting with the 1937 Marco Polo Bridge Incident. This sparked a Japanese invasion. While major port cities and swaths of northern China fell quickly, other than flare-ups, the situation changed little until 1944.Japanese World War II military conquests. Source: David RumseyImperial Japans mind-boggling victories early in the war made the Empire look unbeatable. Even the fortress city of Singapore fell to Japan in April 1942. However, when the United States entered the war, the tide changed drastically with the Battles of Midway, Guadalcanal, and New Guinea. As the successful and rapid American island-hopping campaign came ever closer with each victory, the Home Islands became vulnerable to strategic bomber attacks. In China, Japan learned that B-29 bases had started construction or were completed by late 1943. The huge B-29s range and size allowed for raids against Japan. In response, Japan planned a vigorous offensive.Preparing the OffensiveOperation Ichi-go. Source: WW2DBThis offensive needed to accomplish several goals. First, the airfields in central China had to be destroyed. Secondly, connecting the north-to-south rail lines would enable uninterrupted communications between Korea and occupied French Indochina. The unrelenting Allied submarine attacks by 1944 had decimated Japans shipping, and this rail would bypass that danger. Finally, it aimed to wipe out the engaged Nationalist Chinese armies in southern and central China.To prepare, Japan assembled an army of 400,000, including divisions transferred from Manchukuo and Korea. In a rare move for the Imperial Army, the Ichi-Go armies also received 800 tanks and 15,000 motor vehicles. Given Japans tough strategic situation, such provisioning shorted other armies of needed equipment.Japanese troops performing a close combat attack on Yeh-Han Railroad, 9 July 1944. Source: Wikimedia CommonsThe Imperial Armys actions did not go unnoticed. Due to demands for men, ammunition, and materials from other theaters, few battles happened in China. Now, several sources warned the Chinese Nationalist government and the Americans. Both sides did little, clashing over different military priorities and political goals. The Americans blamed the Nationalists, under Chiang Kai-shek, for not doing enough. They accused Chiang Kai-shek of holding onto nearly 500,000 soldiers to fight the Communists later. This allowed the Japanese, before Ichi-Go, to transfer divisions to fight in the Pacific. Kai-shek also ignored the corruption among his generals, who were pilfering American supplies.Operation Ichi-GoBoeing B-29. Source: NASAOperation Ichi-Go launched on April 19, 1944, in central Chinas Henan Province with Operation Kongo. By the end of May, the industrial hub of Luoyang fell with most of the province.The Japanese then took on Hunan Province, clearing Nationalist forces, but at Hengyangs B-29 airbase, the Nationalists fought hard. Both were captured, but with heavy Japanese losses.The National Army fighting the Japanese varied in quality. Some, trained by the Americans, fought hard, but most were raw recruits. The Nationalist Army often did broad rural sweeps to find manpower. Most Nationalist armies hardly fought, melting away as the Japanese invaded. Hostility sometimes got so bad that peasants fought back, killing the officers and capturing the soldiers.Chinese Soldiers Captured by the Japanese Army During The Ichi Go Offensive, November 1944. Source: FlickrThe initiative stayed with Japan into September. When the Imperial Army invaded Guangxi Province, some 150,000-plus Nationalist troops again retreated. Then the three B-29 bases fell. Japanese use of poison gas and tanks helped their advance. But not all the Chinese retreated. At Hengyang, the Chinese troops dug in, evacuating 300,000 civilians in three days. The citys airfield had housed B-29s until days before the attack, and two rivers joined here, making the city an important communications hub. The Imperial Army attack started on June 23, 1944, quickly surrounding the city.The Japanese expected an easy victory, using their proven tactic of air bombing, mass artillery, poison gas, and firebombs. For 47 days, 18,000 Chinese held out despite little ammunition and a lack of replacements. The Imperial Army attacked three times, finally taking the base on August 8, 1944. The Imperial Army suffered 19,000 killed out of 60,000 casualties.A Chaotic ConclusionNationalist leader Chiang Kai-shek. Source: United States NavyIn September, Japanese forces took US airbases at Guilin, Liuzhou, and Nanning in Guangxi. Again, the Chinese largely let them take these bases as the underprepared Nationalist troops were unwilling to fight. But by November, the Japanese advance had slowed significantly due to heavy losses. This gave the Americans plenty of time to move their bombers to new bases from which they could still reach Japan. Growing casualties and overextended supply lines, combined with minimal impact, forced the Japanese to end their operations.Operation Ichi-Go cleared out the Nationalist Chinese from nearly three provinces and wreaked political chaos. Tensions between Nationalist leader Chiang Kai-shek, President Roosevelt, and General Stillwell (American theater commander) blew up. Stillwell, backed by Roosevelt, demanded control of all Chinese forces. Kai-shek balked, seeing Stillwell as interfering, and he demanded that the American be replaced.While Chiang Kai-shek was successful in removing Stillwell, his mismanagement of Chinas defence against Japan diminished his popularity both at home and with his American allies. This would contribute to the Nationalists fleeing to Taiwan and the rise of Mao Zedong in 1949.An Empty VictoryJapanese plane, Caroline Islands. Source: U.S. NavyJapans last great World War II offensive came as a last gasp. Irreplaceable equipment and trained men needed elsewhere were lost. Operation Ichi-Go captured airfields and connected Korea and Vietnam. However, the Americans just shifted the B-29s to the closer and newly conquered Marianas, much closer to the Home Islands, allowing the bomber offensive to continue. Meanwhile, Japan lost over 100,000 troops, plus heavy material losses of artillery pieces, tanks, and bombers.