The other thread wasn't the help I was looking for. I've now defeated it 3 times and here's what I do.

First, know the AI priorities:

1. Take as many neutral territories as you can
2. Favor spaces that capture a region bonus
3. Favor spaces that capture a mega-region bonus

Steps to win:

1. Capture the starting zone in 3 turns
2. 2 in Nelson to attack Christchurch, Rush into the neighboring 5/4 regions
3. Complete capture of New Zealand, continue into 5/4
4. STOP advancing in New Zealand. You will see the Japan player take Tasmania while you capture 5/4.
5. When you see the Australia player, he's focused on all the neutral territories. So Rush into him like he's just more neutral territory. Favor taking regions from him that remove his region bonus. Avoid neutral regions next to him as that's what he's attacking next.
6. Rush to Wyndham and keep the AI out of West Australia.
7. From here, keep pushing into AIs that are exploring neutral territory. Push North the moment you see a weakness and get into the back territory of all the AIs to continue growing while they fight over region bonuses.

I want golden star.
how to get golden star?

This is not only for a single player map.
I am playing a diplo with a huge AI above me (got booted), which can easily annihilate me, but got swaths of space in Sakha to conquer. I am Pakistan, and I was suspicious that why didn't the AI invade me until I saw Eastern Russia being free land.

Thank you.