So, I'll start this by saying that I am a layman here and look at this from the perspective of mostly being savvy on the Japanese side of the war rather than the European theater. That said, I studied a lot of japanese history in college and continue to read on the subject. My most recent memories draw on conclusions derived from Ian Toll's Pacific War trilogy and Saburo Ienaga's The Pacific War, 1931-1945: A Critical Perspective on Japan's Role in World War II in addition to the lessons learned in college and other materials (as an aside, I believe I got recommended both of those authors from this subs recommended book list)

To your question: There is quite a bit of inspiration taken from the west in what is commonly referred to Modern Japan which emerged in 1868 with the rise of the Meiji emperor and conscious effort to modernize in the western way. This was spurred partially from observing how China remained relatively traditional and was simply steamrolled by Western powers during the Opium Wars and subsequent conflicts.

In other words, the path to self-sufficiency on the global stage was adopting the best of the west and merging it with Japanese identity. Important in this process is the Meiji Emperor as both head of state and mythological figure descended from the gods. Through him and his position, the people followed. This is something that the actual leaders of the country (the military and the Prime Ministers that they liked) abused time and again.

This idea of self-sufficiency through emulation (and eventually surpassing the west) saw it's first major leap forward in the Russo-Japanese War. It resulted in the first major victory of an Asian nation over a Western power. And is continually referred to in subsequent Japanese discourse as a massive step forward that should be built upon.

Concurrent with these military efforts and expansion, was a move towards a much more, for lack of a better word, fascist form of government and thought. This skips a whole hell of a lot of events but there was increased militarism, increased and violent suppression of dissent against the ruling party, and increased fanaticism that swept the nation in the decades after the Russo Japanese victory. The Japanese leadership saw themselves as a race as superior to other asian nations in ways that echoed the imperialist and colonialist actions of the West.

The above resulted in a consolidation of power in the hands of what can only be labeled as zealots at the head of the Army and Navy who really came to rule the nation. To the point where the nominal head of state, the Showa emperor Hirohito was often rubber stamping actions post facto in order to save face. They saw increased military action and expansion as the only step forward for Japanese to claim supremacy of the region.

You've noticed that what I describe sounds a whole hell of a lot like what happened in the European theater and that's not necessarily coincidence. Concepts like Eugenics and Racial superiority as justifications for aspects of a war machine were popularized in and around the times that the both Germany and Japan were building their power.

This ultimately all coalesces in China where the actions of junior officers of the Japanese military kicked off decades of absolutely brutal occupation in the region. I have to underline the brutality here because it was also part and parcel of how the military ran. Within the military conscripts could expect to be beaten by their superior officers while training, the actions on the ground of those soldiers included some of the most horrific war crimes of the era and junior officers quite literally forcing superior officers to sign off on their actions via gun point among so many other things.

From there, Japan continued to expand its activity throughout the region both as policy and as a matter of necessity. Japan is a war resource poor nation and the sheer scale of their war machine stretched across a huge area meant they were in constant need of supplies. They attacked the US thinking that such a sudden and disastrous action like Pearl Harbor would shortly force the US out of the war before resources could potentially become scarce. It turned out to be one of the worst choices they could have made but only after the US won the battles of Midway and Guadalcanal later in the war.

So back to your question: Are the actions in the European theater and the Pacific theater intrinsically linked? I would say yes at least to a degree. Japanese thought leaders were very savvy and took many lessons from WWI, broader military trends and pseudo-scientific theories that propagated in the early 20th century. They specifically looked to the systems and actions of the West to help them get a jump start and eventually become a global force to be reckoned with.

However, I would not go so far to say that the reverse was true. The same race based theories that fueled aspects of the Nazi machine led to them thinking Japan was merely an interesting sideshow and convenient ally rather than a source of inspiration.

As you can hopefully tell, this is a very complex topic. It involves ideas of national identity, the rapid modernization of the world in the industrial age, the rapid growth of global communication methods, and so much more. I attempted to be as accurate as my years of interest in Japanese history has allowed but I'm sure there are actual experts here who can chime in and correct or augment where needed.