How did the unequal treaties weaken support for the Tokugawa shogunate?

The signing of unequal treaties by the Tokugawa shogunate significantly undermined its authority and legitimacy, serving as a primary catalyst for its eventual collapse.12

The shogunate’s inability to resist the demands of Western powers—such as those presented by Matthew C. Perry—to end Japan’s long-standing policy of national isolation (sakoku) was widely perceived as a sign of weakness. By signing agreements like the Treaty of Kanagawa and the Harris Treaty, the shogunate granted foreign powers humiliating judicial and economic privileges.312

These concessions directly contradicted the shogun’s traditional role as the "subduer of barbarians" and his duty to protect the nation. This failure fueled the rise of the "Sonnō jōi" ("Revere the emperor! Expel the barbarians!") movement, which used the shogunate's perceived subservience to foreigners to embarrass the regime and rally support for the imperial court. Ultimately, the government's inability to manage these foreign pressures while maintaining domestic control left it isolated and ineffective, leading many to demand the restoration of direct imperial rule to unify and strengthen the country.24