Recollections of former Imperial Japanese military personnel paint a picture of peer pressure and optimism fueled by Germany's victories across Europe as putting Japan on an unstoppable path toward the Pacific War. 

These accounts blame the "mood of the time" for leading to the Japanese surprise attack on Pearl Harbor 80 years ago, even as the Second Sino-Japanese War was in full swing at the time.

Once a pro-war sentiment settled in, war became inevitable despite opposition from many in the government and the military who secretly opposed it, according to the accounts of elite officials during the wartime period.

That inevitability spurred Tokyo to launch a no-win battle against Washington. 

The Japanese military attacked Pearl Harbor on Oahu island in Hawaii in the early morning of Dec. 8, 1941, Japan time, opening the Pacific War, which lasted more than three years and eight months.

PRECURSOR TO PEARL HARBOR

A year after the 1931 Mukden Incident, which marked the beginning of Tokyo’s invasion of China, the Japanese puppet state of Manchukuo was established.

The Marco Polo Bridge Incident took place 15 kilometers southwest of what is now Beijing in 1937 to signal the opening of an all-out war between the Asian neighbors.

At around 10:40 p.m. on July 7, an unidentified individual opened fire on the Japanese military during its training exercises. Nearby units from Japan and China fought a small battle following the assault.

Both the local officials and the General Staff Office in Tokyo initially wanted to “stop the hostilities from spreading further.” With that in mind, Maj. Takeo Imai at the military office within the Japanese Embassy, who was knowledgeable about political affairs in China, was involved in peace negotiations alone.

Imai contacted a senior Chinese military official and had the Chinese side accept a proposed agreement on July 11, under which Japan and China were supposed to withdraw their corps from the bridge upon signing of the agreement.

After he returned to report his achievement, Imai was met with unexpected news: the General Staff Office had changed its stance so that reinforcements would be sent in the name of protection of Japanese citizens there.

A local staff officer told Imai that he “should not continue unnecessary negotiations now and must abandon the agreement if you have reached one” in line with the decision by the General Staff Office.

Although Imai refused the request, other staff members around him who had previously kept a neutral stance began taking a hard line, and they criticized Imai, who asked that talks should be continued, for being “too soft.”

Referring to the circumstance he faced then, Imai lambasted his colleagues for “having suggested reckless hawkish plans without due consideration” in his book “Shina Jihen no Kaiso” (Reflection on the Second Sino-Japanese War), released after the war’s end.

In the 1964 title, Imai, at the same time, described the other officers’ behavior as being “not enough to be deemed as surprising if taking into account the ambience of the time.”

Responsible for determining the policy in the General Staff Office was Maj. Gen. Kanji Ishiwara, who had just been promoted to head of the No. 1 strategy division in March 1937.

Whereas Ishiwara took initiative in the Mukden Incident when he had been a lieutenant colonel as part of senior strategy staff at the Kwantung Army, he did not want the hostilities to accelerate over the Marco Polo Bridge Incident because he believed the conflict would “only continue going terribly.”

But few core military officers supported Ishiwara. Col. Kaneshiro Shibayama, chief of the Army Ministry’s military duty division, was among his backers. Shinsaku Tamura, an Asahi Shimbun reporter working with the Imperial Japanese Army, saw Shibayama surrounded and questioned aggressively by pro-war personnel at his office.

“The circumstance was just like in the form of bullying that had once been rampant among junior high school students,” wrote Tamura in his later years, looking back on what he watched at the time.

Driven by the backlash, Ishiwara had no choice but to dispatch soldiers. The Imperial Japanese Navy’s land forces started combatting the Chinese military in Shanghai in August, expanding the field of battle.

On Dec. 13, Tokyo took Nanking, the capital of the Nationalist government headed by Chiang Kai-shek, bringing about what is currently known as the Nanking Massacre.

As Chiang had already relocated to the new capital of Chongqing for do-or-die resistance on Nov. 20, the Japan’s invasion eventually came to a dead end as feared by Imai and Ishiwara.

JAPAN JUMPS ON BANDWAGON

The United States and Britain expressed their assistance for China, and offered relief goods through French Indochina (today's Vietnam) and British Burma (current-day Myanmar).

After World War II broke out in September 1939 with Germany racking up easy victories in the early stages, calls grew in Japan to form a military alliance with Germany so that Tokyo would “not miss” the chance.

Under such a circumstance, Japan tried to block the logistics route for the Chiang government and secure resources in southern regions by advancing to the northern part of French Indochina in September 1940.

This drew strong opposition from Washington, resulting in the U.S. decision to impose economic sanctions on Tokyo. More than three-fourths of Japan’s oil imports came from the United States then, while iron material from the nation accounted for nearly 70 percent of total imports as well.

As Japanese officials primarily in the Imperial Japanese Army became increasingly supportive of plans to open hostilities against Washington, Zenshiro Hoshina, who took office in November as head of the Navy Ministry’s armament bureau, strongly objected to war.

Despite his opposition, Japan’s invasion of the southern region of French Indochina in September 1941, combined with the Tripartite Pact between Japan, Germany and Italy, prompted the United States to prohibit all oil exports to Japan.

According to Hoshina’s memoirs, “Daitoa Senso Hishi: Ushinawareta Wahei Kosaku” (Hidden history of the Greater East Asia War: Lost peace overture), published in 1975, officials from the government and the Imperial General Headquarters, an organ under the emperor, discussed whether to go to war for as long as 17 hours at a meeting on Nov. 1, 1941.

Notes made at the time by Hoshina show Navy Minister Shigetaro Shimada expressed his stance during the session, stating, “There are no other good proposals … We have no choice but to make up our mind to launch a war.”

Following the meeting, Hoshina asked Shimada “why you did not make clear the Navy’s opposition.”

Though Shimada admitted that the Imperial Japanese Navy “does not want to engage in warfare between Japan and the United States,” he also said the Navy’s “expression of an objection in this stage could lead to civil war” within Japan.

Hearing the response, Hoshina said he realized why his argument to avoid hostilities with Washington was rejected.

“Dazzled by the easy victories of Germany in Europe, officials totally failed to consider future prospects and simply acquiesced to the majority’s sentiment,” Hoshina said.

At 6 a.m. on Dec. 8, a month or so after the meeting, the Navy and Army in the Imperial General Headquarters announced the Pearl Harbor attack by saying, “The Imperial Army and Navy have entered a war with the United States and Britain early in the morning in the western Pacific.”

This was the beginning of Tokyo heading down the path toward its disastrous defeat in 1945.

GOING ALONG WITH PREVAILING MOOD

In the 1980s to 1990s after the end of World War II, ex-Imperial Japanese Navy commissioned and other officers held meetings to “reflect on” the conflict on more than 130 occasions, contemplating how the Pacific War was launched and lessons learned from the momentous blunder.

According to the gatherings’ records, Atsushi Oi, a former captain who served as part of a combined fleet’s staff, asked, “Did anyone in the Navy believe Japan could win that war?”

In response, Takaji Terasaki, another retired captain who was a staff officer for the aviation squadron, explained what was at the center of the problem in the Imperial Japanese Navy’s decision-making.

“The worst point is that the Navy was always swayed by the prevailing sentiment while making excuses … It did not oppose it thoroughly … It was motivated by the mood of the time,” Terasaki said.

Tameki Nomoto, an ex-rear admiral who was the chief of staff for the air command, agreed.

“We were trained under the assumption that we would surely fight a war against the United States … that shaped the mood in the Navy,” said Nomoto.

Kazushige Todaka, 73, director of the Yamato Museum in Hiroshima Prefecture, who was then a member of a historical record examination group, helped organize the former Imperial Japanese Navy officials’ meetings.

Todaka, who has also compiled 11 volumes of the gatherings’ records afterward, analyzed what was behind Japan’s reckless decision.

“One of the factors leading it (Tokyo) to start a war which it knew the nation could not win was peer pressure, or the atmosphere,” said Todaka. “War is part of an extension of diplomacy but it (Japan) is poor at negotiating. 

"The tendency to criticize some officials who are seeking a compromise with other nations for being weak-kneed exacerbated the situation through groundless optimism with no points of compromise envisioned.”