There were many great armies in WW2. The Brits, Americans,
Germans, Finland are some notable ones.
But the Japs were probably the best, in my opinion.
Their only drawback was their lack of quality and quantity of
weapons.
Even before WW1 during the Boxer Rebellion when 8 countries united
to fight China, the Japanese troops were the most competent,
disciplined and brave. The Russians were the worst and the French,
Italians and Germans were pretty bad. Of course the Chinese were
hopeless.
Later on, sometime before WW1, the Japanese Navy destroyed the
Czarist Russian Navy during the Russo-Japanese War over Manchuria.
Yes - destroyed.
And in WW2, I'm sure you've already heard how fanatical the Japs
were and usually fought to the death etc etc. In fact, some
ignorant fools were still hiding in the jungles long after WW2 was
over ready to die for their dog emperor.
That they lost (fortunately) was entirely because the Americans'
desire for vengeance for Pear Harbour and their industrial might
simply crushed the Japs.
The Japs were already losing in 1945, some argued that there was
actually no need for 1 atomic bomb much less 2. So you can guess
that how deep the American's hatred was for the Japs at that
time.