Might be good to get a warning sign that the AI wants to take over the world because it will start amassing troops near Siam and if it does manage to conquer Australia, you can be relatively sure that it will spend a few turns building up its bottleneck defense, maybe trading some border country to get a card each turn.

Lol that just reminded me of the first time I played risk with my cousins, when we thought that players got a card each time they took a country and then the 5 card max rule meant that they could (or had to) trade in for troops in the middle of their turn. The game had a few quiet turns and then absolutely exploded once things got rolling and only lasted some turns after that because we weren't the most strategic thinkers and didn't realize there was no reason to stop when you could reinforce your front with more armies than anyone else had combined every 3 countries you took.