At the end of turn of the twentieth century, after decisive victories over the crumbling Chinese and Russian empires in warfare in the Eastern Pacific, Japan was an ascendant world power intent on dominating Asia. The Japanese emperor had recently been restored to head of the modern state, and a parliament formed after centuries of military feudalism and isolation. Japan wanted to catch up with the industrialized West and did so very quickly, borrowing from the German model. With their newfound technological and productive capacities, traditionally inward-looking Japan set its sights on establishing its own naval empire, just as the United States was also emerging as a a rival to Japan with its control of the Philippines, Guam, and trade concessions with Qing China.

As a growing island nation with limited resources and a limited labor force, Japan needed to expand its food and raw material supply as well as its workforce, since all able-bodied Japanese men were expected to serve in the military. With its presence already established in Northeastern China, the Japanese military annexed the Korean peninsula, whose people the Japanese believed to be inferior. For decades of occupation until the end of World War II, Japan extracted food, materials, and labor from the the Koreans, even enslaving young women for sexual service to the Japanese military.

With the Russian and Chinese states collapsing during World War II, Japan became the stand-alone regional power, though it was not yet confident enough to directly challenge the Western forces on their doorstep. With increasing audacity, Japan flexed its might in the absence of significant resistance by invading China through Manchuria in the early 1930s, unleashing a brutal occupation of the Chinese mainland and Taiwan, which resulted in the deaths of hundreds of thousands of Chinese civilians through murder and deprivation. With so much territory secured in Asia, Japan was able to construct a series of air and naval stations on strategic islands dotting the Pacific and Indian Oceans. With their military machine at full strength, Japan was now a serious threat to Australia, a British commonwealth, and to the Pacific territories of the US.

The Japanese attack on the American fleet at Pearl Harbor in Hawaii, as the ultimate expression of Japanese imperial self-confidence and hubris, also proved to be its most consequential. Drawing the fiercely isolationist US into war with Japan, key victories in bloody Pacific naval campaigns eventually turned the tide against Japan. Despite the decimation of their forces, the Japanese empire would not surrender, and so the US considered a full-scale invasion of Japan the only way to end the fighting. Projections about the destructive costs of a land invasion for both sides were analyzed by the American government, and the astronomical predictions led to the development of the atomic bomb as a more humane alternative. In August of 1945, the Japanese Empire became the only victim of an offensive nuclear weapon twice over, as the US bombings finally caused the Japanese to surrender. In the many decades since the end of World War II, Japan has been demilitarized and has sought to make amends and seek forgiveness for its historic atrocities.

There were few, if any, positive aspects to Japanese imperialism; only negatives. The Japanese conquest of much of East Asia led to bloodshed, suffering, and death on a truly monumental scale.

One of the most notorious atrocities committed by the Japanese was the Rape of Nanking, when the Imperial Army committed mass murder and rape over the course of several weeks after capturing what at that time was the capital of China.

Japanese rule in China and other countries throughout East Asia was notorious for its harshness and cruelty. Primarily, this was because Japanese nationalism, which supplied the ideological foundations for imperialism, was steeped in notions of racial and cultural superiority.

The Japanese believed that their alleged superiority gave them the right to treat so-called lesser races however they pleased. And they did, subjecting them to appalling treatment as the Japanese empire grew rapidly.

As well as being cruel, Japanese imperialism was also exploitative. Lacking raw materials of their own, the Japanese took what they could get from the lands that they conquered, bringing considerable impoverishment to indigenous populations.

In some of the conquered territories, famine broke out. In the Dutch East Indies (modern-day Indonesia), it's estimated that somewhere in the region of four million people died as a result of famine and forced labor under the Japanese.

Overall, then, it's no exaggeration to say that the impact of Japanese imperialism was completely negative and constitutes one of the darkest and most tragic episodes in human history.

Japanese imperialism led to numerous human rights violations in China, Korea, and the Philippines. Millions would die from torture, ill-treatment, or scientific experiments performed by sadistic Japanese doctors who used prisoners of war to obtain unwilling lab participants. The Japanese army and navy competed with each other for prestige within the government and sought greater conquests at the expense of the Allied powers, who were mainly concerned with Hitler's war machine in Europe. After Pearl Harbor, the Japanese government faced the might of the United States military-industrial machine and paid dearly. Thousands of Japanese civilians died in firebombings in Tokyo and Yokohama, while starvation was common throughout the home islands between 1944 and 1945, as American submarines targeted Japanese merchantmen at will. The atomic bombing of Hiroshima and Nagasaki was also debilitating, as it proved that an entire city could be leveled with one bomb. Also, the area continued to have increased instances of birth defects due to the radiation from the blasts.

Japan was weary of its territorial vulnerabilities against western powers. This led the country towards its imperialistic path. The country was determined to acquire as much territory in Asia as possible in order to bolster its status economically and militarily. Japan had its sights on Korea, China, and her other Asian neighbors.

In Korea, Japan enslaved the country and led to the country’s split into two countries with the ramification of that being felt until this day. The split created the democratic south and the dictatorial north with the two countries constantly at the threat of war. Further, Japan led to the deterioration of Korea’s cultural system by forcing the citizens to adopt Japanese culture, language, and religion.

Japan’s imperialist efforts led to the Nanking massacre that permanently affected her relations with China. Japanese soldiers murdered and raped Chinese citizens perpetrating one of the worst events in Asian history. Japan also led to the onset of the first Sino-Japanese war.

Japan also had negative impacts of its own. The country suffered economically and allowed for the destruction of its infrastructure. This was due to its failure to comply with other world powers' request to halt hostilities with her neighbors. Japan attacked Pearl Harbor after the United States threatened to cut off her oil supply, due to Japan’s occupation of China. This resulted in the bombing of Hiroshima and Nagasaki and the loss of a significant number of the nation’s population.