Anyway, let's look at the factors that brought the Militarists to power:
Economic:
It's no secret that economic privation lead to destabilization in Europe, and that this helped lead to the rise of dictatorships. Desperation makes radical solutions seem more acceptable. Of course, Japan was no different. The post-World-War-One economic boom was part of what allowed the growth of Taisho Democracy in the 1920s. (The other major part was the fact that most of the Genro had died by then.)
The good times ended in 1927, when the Showa Financial Crisis began. In my view, there were two main causes for this: Europe had recovered from WW1, leading to greatly increased competition for Japanese exports, and many major Japanese banks were insufficiently capitalized and had over-extended themselves by loaning to these same exporters. The first cause is rather hard to butterfly, but the second is easy enough. Japanese banks didn't need to overextend themselves; in fact, I don't believe they wanted to. However, in this period (much like in modern-day China, and for many of the same developmentalist reasons) Japanese banks lent not just to companies that were expected to be profitable, but also to further state aims. A stronger split between the banks and the government, then, will make this financial crisis less severe, and therefore remove one of the factors that lead to the Militarist takeover.
In the grand scheme of things, the Showa Financial Crisis was relatively minor. Japan had suffered through banking crises before, and would again. The Great Depression was a larger hurdle. People have mentioned that Japan suffered less from the GD than did many other countries, and this is true. As they noted, the industrialization of Manchuria (Manchukuo) helped the Empire through the crisis. But of course, that invasion is one of those things we need to butterfly, as the seeming economic success of that move helped legitimize Militarist rule. Also, real rural incomes declined by over 50% during this period. While it wasn't as bad as in some other nations, it was still quite bad, and lead to much instability. A world that does not experience a Great Depression will be much less likely to see a Militarist Japan, or a Nazi Germany.
The last, and most important (in my view) factor, is the Smoot-Hawley Tariff. The first few months of the Great Depression in the US actually saw an
increase in Japanese exports to that nation, as newly budget-conscious buyers started buying cheaper Japanese goods in preference to more expensive (though often better quality) domestic goods. Fear of just this sort of trend is part of what lead to the extremely high tariff passing in 1930. That tariff, and the retaliatory tariffs that followed it, lead to a decline in world trade of nearly two-thirds. For a nation that survived on exporting, this was devastating. Japan had to import (now much more expensive) raw materials, transform them into manufactured goods, and then sell those abroad, to pay to import (now more expensive) food. It was an existential threat. At this time Japanese goods usually competed because they were inexpensive, so these tarrifs usually priced them right out of the market.
Zmflavius wrote on the front page about how the support of the zaibatsu families was crucial to the success of the Militarists. He is absolutely correct about that. However, I will (kindly) disagree with his dissertation that the zaibatsu power bloc usually supported an aggressive foreign policy. In my view, the opposite was usually the case. This power bloc advocated for a small foreign policy. Of course the concessions were a vital part of their business strategy, and they favored a strong defense of them. But overall they favored good relations with as many nations as possible.
As a newly-industrializing nation, Japan occupied a strange niche in the world market. Her balance-of-trade with the industrialized nations, especially Europe, were perpetually in the red. This was because Japanese companies were usually importing expensive manufacturing equipment to develop their own factories. Her trade with East Asia, in contrast, was usually quite profitable, as it exported manufactured goods and received primary goods (foodstuffs, raw materials, etc) in return. Japan needed to maintain good relations with Europe, so that it could continue to import machinery and develop. But she also needed strong relations with East Asia, so people would agree to buy her goods. The industrialists had seen the effect that Chinese boycotts could have on their goods, and they feared such an effect.
Lastly, the zaibatsu families were the hereditary enemies of the military. Even before the Militarists took over, it wasn't uncommon for military expenses to take up over 30% of the national budget. Naturally, these kinds of expenditures required relatively higher levels of taxation, which the zaibatsu hated with a passion. The zaibatsu flexed their muscles to bring the military home from Siberia in 1922, and many in the military held a grudge. If you actually read any of what the Militarists wrote, if you read their propoganda, most of it is really just hatred against the business leaders. The rich elite were not loyal to Japan, and would compromise national interest in favor of profit. The rich elite had foreign business ties that made them "impure" and "not Japanese". They corrupted the true nature of the nation, which was spiritual at heart. It goes on and on.
So how did the zaibatsu come to favor the Militarists? It's simple, really: they felt like they had no other choice. Before the HS Tariff, they hated them. But after that passed, many felt like exports were simply not an option. At the very least, the Militarists could bring big (and profitable) military supply contracts. At least the factories would stay open. Further, if Japan was going to make things, it needed raw materials. If it could not pay for them, then perhaps the Militarists could simply seize them. Was that not better than going without? Military action would enrage the Chinese, and make them less likely to buy Japanese goods. But people weren't buying Japanese goods anyway. Maybe if the Militarists could turn China into a captive market, the way India was for the British, then Chinese people would have no choice but to buy from Japan. If that huge market was in Japanese hands, then the zaibatsu would never be such a position again.
Really, the alliance between the zaibatsu leaders and the Militarists is a case of politics making strange bedfellows. It was an alliance of desperation, one that never should have happened. It should be easy enough to butterfly...
I have two more sections for this mini-essay planned: Social factors, and government factors. However, I fear this is getting a bit long as it is. I will add in the other two latter. Sorry...
