Final answer:
The Tokugawa shoguns implemented isolationist policies out of concern for maintaining power and stability, fearing that foreign influences, particularly Christianity, could disrupt Japan's social order and threaten their control.
Step-by-step explanation:
The Tokugawa shoguns were concerned with maintaining power and stability within Japan, leading them to enact isolationist policies to limit foreign influence and potential unrest. Foremost, they were worried about the spread of Christianity by European missionaries, which could undermine the neo-Confucianist social order they preferred and lead to divided loyalties among the daimyos. To curb this, Tokugawa Ieyasu and his successors expelled most foreign missionaries and restricted trade primarily to the port of Nagasaki. The fear extended to the Japanese populace, who were forbidden from traveling abroad to prevent the importation of foreign ideas. Although the shogunate engaged in limited trade with select countries like Great Britain and the Netherlands, their overall goal was to maintain Japan's cultural and political autonomy during the Tokugawa period to avoid the fate of other nations that had been dominated by Western powers. The strategy was largely successful until the arrival of Commodore Perry and the forced opening of Japan in the mid-19th century.