Final answer:
Japan's geography assisted in restricting European access through isolationist policies that limited foreign trade and residence to specific controlled areas, and by banning most Japanese from traveling abroad.
Step-by-step explanation:
The geography of Japan played a crucial role in its decision and ability to restrict European access during the Edo period. Japan's isolationist policy, known as sakoku, effectively limited European influence and kept the country closed to most foreign nations. The Japanese government enforced strict rules that confined foreign merchants to specific areas such as the Dejima Island in Nagasaki for the Dutch and a Chinese enclave also in Nagasaki. Ieyasu's banning of Christianity and the subsequent 1639 exclusion of the Portuguese were influenced by the fear that foreign religions and ideas could undermine the social order.
Additionally, by dictating that all trade was limited to certain controlled ports and enacting laws that prohibited Japanese from leaving the country with few exceptions, the shogunate ensured that internal stability and control were maintained. The sakoku policy was effective until Commodore Matthew Perry's arrival in 1853 forced Japan to start making concessions, which eventually led to the end of isolationism and the collapse of the Tokugawa shogunate.