How do I beat japan

[BootlegRussian]

alright so Im playing as democratic Yugoslavia, and have pushed all the way to Manchuria and liberated Korea, but now I can't get past them, and i accidentally promoted one of my commanders so now all his positive traits went to hell. and they're pushing really hard on me and have multiple naval invasions in Vietnam and eastern china. any advice on what I should do oh and btw this is one of my first campaigns.

***UPDATE****
so I'm actually managing to defeat japan and it's going pretty good but Im still going to try paratroopers, oh and also america joined the french entente alliance (which I am in) and is now helping out.

 

[pdx mm]

I found it is easiest to just build a decent air force and use it all to get air superiority long enough to para drop. If you lucky you can secure a port to get your army to home island. Since you already have Korea then you only have that one box to hold.

 

[BootlegRussian]

I found it is easiest to just build a decent air force and use it all to get air superiority long enough to para drop. If you lucky you can secure a port to get your army to home island. Since you already have Korea then you only have that one box to hold.

I have a pretty huge air force but never bothered to research paratroopers, and for some reason whenever I have any kind of units on the home islands all the supply just disappears

 

[pdx mm]

You need to control a port to get supplies if you are the invading party. Now one thing you can do is try to build a port on the tile you land on if it doesn't have one but you will most likely be constantly attacked which puts a stop on all construction. What I do is land a few divisions on some random tiles near where I really intend to take to draw their forces away. Those first droppers will die but it is for the cause.

What do your divisons look like? In my experience you don't want wide combat width divisions for the first drop because that will also hurt your supply. My para drop dudes are 10 width with my defense units being 20 and 40 wide. I usually use 12 divisions, stacks of 3, in 4 different spots as my distraction so they don't die to fast and have up to 24 regular soldiers ready to sail for defense with many more ready to come. You will have to keep at it as Japan does a great job defending their island.