Hokushin-ron directed Japanese expansion north into Soviet territory. Its appeal rested on the assumption that Russia's civil war had left the country militarily weak, but Soviet forces proved far better prepared than expected. The comparison with the United States after its Civil War makes the larger point that internal conflict can leave a country with experienced veterans rather than immediate military helplessness. Once northern expansion failed, the alternative southern strategy became more important to Nagano and other Japanese planners.
Chapter · 7:50-9:53
Why Japan's northern expansion strategy collapsed
The northern-expansion idea treated the Soviet Union as a tempting target, but Japan found its presumed weakness badly misjudged.