Italies main weakness was Mussolini, who pretty much fucked up everything you could fuck up.
Of all the 7 large powers Italy had, in most areas, the were bad, but not the worst.
Comparing them with other large nations, you see that, while not a Super power, they had some arguements for them.
- Navy : Stronger than germans or Soviets and not that much weaker than the french.
- Army: Not super modern but at least until 1941 half-way decent armoured troops and standard infantry ( still better than the japanese, who sucked in this regard)
- Air Force: Quite good actually, but it was to much split apart and wasted by Mussolinis stupid ideas.
- Economy : meh, great lack of fuel, relativly small industrial base compared to Britain or germany, but still, shouldn't be much weaker than Japan.
CHina on the other hand was a mass, a few well trained division and a few military factory, all build and trained by Germany and lots of bad equipped and trained soldiers. Whats most important for China not to be considerd a major power, is its near total lack of an Air force or navy.
And Japan.
Japans overrated, Japans really overrated.
Compared to Germany, Britain, THe USSR and the US, Japans industry was still rather small. Navy was well trained and equipped, Airforce too.
But the Army was a joke.
Few Artillery, hardly any tanks, not much motorization. THis wasn't important during battle on islands against US-Marines.
But the Sowjets, they would have crushed the Japanese in an all out war.
Japan is very overrated, because it was the last Axis power to surrender and because it kicked butts during the first months.
But, until the US enterd, they never faced a serious enemy.
The Chinese were terribly equipped and had wasted most of their elite troops in the first battles.
The British were focused on Europe and got suprised and the Dutch were jsut the remains, since the homeland was occupied.
Once Japan faced an real opponent, they quickly lost ther fortune.
Within a year, they lost every ace and advantage their had, first their carriers and than their planes.
Everybody who believes that the Japanese, even with their whole army could really beat the USSR, must be joking.
Maybe with air superiority, but even then, really hard.
Russia, the USa and to a lesser extent Germany could loose troops, equipment and pilots, they had enough capacity to build and train new ones.
Japan, Italy and China could not, every tank, every rifle they lost was far worse for them then for the others.