Spoiler Alert: they invaded other countries because they wanted their stuff

Link to article?

I’ll go a bit earlier than the video.

In the Edo period, from 1603 to 1868, you have the consolidation of power in a rather isolated Japan, under military leaders called shoguns.

Then, in the Meijin era (from 1868 to 1912) the emperor is restored, the country resumes contact with the outside world, and there’s a campaign of modernisation. But the centralisation from the Edo period remains there, and gets further strengthened over the head of the emperor.

When combined, you have a country changing its means of production from feudalism to capitalism. However, a change in means of productions cause a change in the forces of production, and those create a need for materials. As the video says: oil, rubber, iron etc. And the solution found was Europe Japan scrambling for Africa the Pacific.