Japan definitely got its nose bloodied by the bear in 1939.
Quite often in reading of this era, I’ve wondered, “What were they thinking!?” with regard to the northern strategy. You can’t just eat China. Korea, sure. China...nope. It’s a dog chasing a truck scenario.
However, their soldiers and pilots got a lot of practice out of it, and a few years later they were able to mop the floor with the British and Dutch in Malaysia, not to mention the natives.
What they needed to wage war was always in the south. To this day, the shipping lanes are potentially very problematic for China, and that’s in spite of pipeline technology.
I guess a lot of the military were suffering from the Maginot Line fallacy, looking backward to yesterday’s problems to guide them with today’s challenges.
But heck, they hadn’t even the people needed to take over any substantial piece of China. There were half a billion Chinese at the time, iirc. What were they thinking!
What the navy needed was in the south. Army leadership was rabidly anti communist and wanted to take after the USSR until their ardor was dampened and credibility reduced by Khalkhin Gol.
Anyway, Japan defeating China was about as likely as was Japan defeating the US. What were they thinking, indeed.