Cause of expansion after WWI

Dears, I am going to have an exam on Friday about the cause of Japan's expansion and the rise of nationalism after the WWI and how these led the the involvement of the WWII. I would like to get some idea from you guys.
Personally, I think it is the traditional influence of Mito School and Shintoism PLUS the worse economic codition.
However, some historians states that the Liberal 20s had a rather big influence. How would you consider this statement?

Thanks

That's a big topic. Are you specifically looking between the wars? I think there's a lot of continuity going right back to the Meiji Restoration.

Looked at strategically though, I think the First World War created an Asian power vacuum into which Japan would inevitably try to spread. Minimal fighting had given them Germany's Asian possessions, France and Britain were shell-shocked and Russia collapsed into civil war. Analyzing the war of economic exhaustion that had happened in Europe strengthened the sense that security required a directly controlled resource base.

It's also at this point that the seeds of the Pacific War are planted. It was largely US pressure that made Japan give up its puppet state in Vladivostok, and the 8/8 fleet expansion was funded to avoid having to back down in the future. Though the Washington Treaty headed off an arms race, influential elements in the Navy still came to view war against the US not in terms of "if" but "when."

War might have been avoided had Japan tried the Shidehara strategy of trying to reach a modus vivendi with the West, meanwhile dominating Asia through more of a "soft power" approach. But as hard-line elements increasingly dominated the services and, through them, the government, the logic of those beliefs pushed Japan into being more adventurous and provocative rather than less.

You're right though, "Taisho Democracy" is the domestic context in which that decision was made. Any good sources you'd recommend?

I suggest the 20th century Japan by Andrew Gordon to you. there are clear evidences showing the full picture of what's happening.

Thanks, is that "Labor and Imperial Democracy in Prewar Japan (20th Century Japan)." I'd link to the Amazon page but am still not allowed to. They list it as published by the University of California Press.

The writeup suggests that it argues "the intense polarization of laborers and owners during the Depression helped ultimately to destroy the legitimacy of imperial democracy." Does that sound like a fair summary?

When he talks about labor, is that just industrial labor or is farm labor included? My understanding of this era is that the highly nationalistic junior officers came largely from fairly poor farming families. Does that seem to be a cause or an effect?