Even as the emperor's troops got bogged down in China, skirmishes on the borders of Manchukuo and the Soviet Union were threatening to get out of control. Officers of the Kwantung army, such as Colonel Tsuji Masanobu, a maniacal soldier responsible for all manner of outrages before the war was over, were itching to attack the Soviet army. Tsuji was a proponent of the Strike North faction, as were most members of the Imperial Way [faction; or Kodoha]. They wanted to contain the Soviet Union by taking control of eastern Siberia. General Araki Sadao, who was, rather absurdly, Prince Konoe's education minister, once said that if the Soviets did not cease to annoy japan, he would "have to purge Siberia as one cleans a room of flies."UPDATE: In the comments, Danny Yee questions whether a determined Japanese effort against the Soviets might have achieved victory and possibly even allowed the Nazis to best the Soviets in the West. It's an interesting question of alternative history. But, judging from the book In the Service of the Emperor: Essays on the Imperial Japanese Army, by Edward J. Drea (U. Nebraska Press, 1998), reviewed here and here, the IJA's serious deficiencies in logistics and heavy weaponry would have made a decisive northern victory very unlikely. Plus, they were fighting against Marshal Zhukov (although the IJA might have kept him away from Stalingrad, and even Zhukov wasn't invincible). I think the IJA would have suffered the fate of Napoleon's army in Russia.
The Strike North faction was largely army based and attracted many junior officers. Those who wished to avoid a war with the Soviet Union and head south instead, where control of the rich natural resources of Southeast Asia would allow the navy to build up strength for an eventual war in the Pacific, were mostly admirals, generals, and high-ranking officers of the Control faction [Toseiha]. The emperor had no desire to go to war with the Soviets and was on the whole more sympathetic to the navy. There was, however, no consensus at all about what to do next: cut a deal with Chiang Kai-shek and retreat from China proper; patch things up with the West; prepare for an all-out war with the West; prop up a Chinese puppet regime in Nanking; get even closer to Nazi Germany; strengthen the army, strengthen the navy; strike north, strike south. But as so often happened, Tokyo's dog was wagged by its military tail, once more in Manchuria.
Fighting broke out in the summer of 1938 on the wet and misty borderlands of Korea, Manchukuo, and the Soviet Union. Soviet troops were building a fortification on the Manchukuo side of the Tumen River, and the Japanese decided to test them. The Soviets had bombers and tanks. The Japanese had none, but they set great store on their superior "spirit." After battling for a fortnight, there were many dead on both sides, more on the Japanese than the Russian, but nothing much was gained or lost. The emperor told his general staff to stop the war. Colonel Tsuji ordered his men to go on regardless. Spirit would see them through. Less than a year later, at Nomonhan [Khalkhin-Gol], on the border with Outer Mongolia, the Japanese, armed with Molotov cocktails, sabers, field guns, and some light tanks, attacked General Zhukov's Soviet tank brigades. The fighting on ghastly, mosquito-infested terrain went on for months and ended in a slaughter. The flatlands were filled with Japanese corpses, feasted on by black desert vultures. More than twenty thousand Japanese died of hunger, thirst, and disease, as well as from Russian bombardments. Colonel Tsuji was duly promoted. But the plan to strike north was abandoned. From then on all the action would be to the south.
Drea's lead-off chapter, "Tradition and Circumstances: The Imperial Japanese Army's Tactical Response to Khalkhin-Gol [Jp. Nomonhan], 1939," concludes thus:
It seems commonplace that military defeat can be salutary in nature, because it forces out incompetents and promotes innovative reforms. The popular historian Barbara Tuchman wrote, "Whereas defeat in war galvanizes military development, nothing contributes to military desuetude like total victory." Like most generalizations it overstates the case. The way an army interprets defeat in relation to its military tradition, and not the defeat itself, will determine, in large measure, the impact an unsuccessful military campaign will have on that armed institution.More specifically, Drea finds that the IJA blamed the defeat more on lack of training and insufficient "fighting spirit" on the part of the newly activated Twenty-third Division, which bore the brunt of the defeat. When a blunt Lt. Col. Konuma suggested that "the IJA hereafter would need equal or superior weaponry to fight foreign armies," Maj. Gen. Endo called him an imbecile and accused him of insulting the Imperial Army.
NOTE: Gads. The new Blogger interface is at its most buggy when you try to update and republish a post already published. The first thing it does is unpublish the earlier version. Then it gets worse.