How did the unequal treaties weaken Japan most?

The short answer

• Steam and the Pacific brought America to Japan. The United States had gained California in 1848 and wanted a steamship route to China, which needed coaling stations on the way. American whaling fleets worked the waters off Japan, and sailors wrecked there were sometimes imprisoned. These interests made Japan a stop on a commercial highway for the first time. Perry’s mission was a product of the steam age: his two steamers could ignore the winds that had kept sailing ships at the mercy of Japan’s coast for centuries.
• A government without a navy could only delay. The divided state described in chapter 1 had no fleet, no national army and no means to pay for either quickly. Abe’s officials built batteries on artificial islands in Edo Bay after 1853, but they knew that Chinese forts had been destroyed by ships like Perry’s. Refusal meant war and war meant defeat, so the only open question was how much to concede and how to explain it. The shogunate’s weakness turned diplomacy into a choice between humiliations.
• Consultation widened the circle of decision-makers. By asking the daimyo and the court for advice in 1853, Abe hoped to share responsibility for an unpopular decision. Instead he taught the outer lords and the court that they had a legitimate voice in national policy, which they had been denied since 1600. Once the court was asked, its refusal in 1858 carried weight. A consultation meant to strengthen the government created the alternative authority that would replace it.
• A succession quarrel turned diplomacy into a feud. The question of who would succeed the heirless shogun Iesada split the elite in 1857–58. Reforming lords, including Satsuma’s Shimazu Nariakira and Mito’s Tokugawa Nariaki, backed Hitotsubashi Yoshinobu; the conservative officials around Ii Naosuke backed a twelve-year-old from the Kii branch. Because the same men disagreed about the treaty, foreign policy and the succession became one fight, and Ii’s victory on both turned his rivals into enemies of the shogunate itself.

What it changed

Terror entered politics. Ii’s assassination opened a decade in which young samurai calling themselves “men of high purpose” (shishi) murdered officials and foreigners in the emperor’s name. Political violence became a way to force decisions on governments that could not keep order. The movement drew many of its members from Chōshū, Tosa and Satsuma, the domains that would lead the next stage.

Kyoto became a second capital. After 1858 lords and activists flocked to Kyoto, and the court, powerless for two and a half centuries, became a centre of decision. The shogunate itself tried to repair its standing by marrying the emperor’s sister to the young shogun in 1862. Every policy now needed two approvals, and the emperor’s approval carried the moral weight.

Open ports remade prices and livelihoods. Yokohama grew from a fishing village into Japan’s main trading port, and raw silk became the country’s largest export. Silk-raising districts prospered while urban workers and samurai lost to inflation. The trade also gave Japanese merchants and officials their first close look at Western commerce, knowledge that the Meiji state would later use to build industry.

Russia’s advance redrew the north. By the Treaty of Aigun in 1858 and the Treaty of Peking in 1860, Russia took from China the lands north of the Amur and east of the Ussuri, and founded Vladivostok, whose name means “ruler of the East”. In 1861 a Russian warship occupied part of Tsushima for six months. Fear of Russia would shape Japanese strategy for half a century, through Korea to the war of 1904.