Final answer:
Japan instituted a closed country policy to control foreign ideas. This policy involved severe restrictions on interactions with foreign countries, including a ban on Japanese travel abroad and limited trade with only the Chinese and Dutch.
Step-by-step explanation:
The type of policy that Japan instituted to control foreign ideas was a closed country policy. This policy, also known as Japanese isolationism, was imposed by the Tokugawa shoguns from 1633 to 1853. It involved severe restrictions on interactions with foreign countries, including a ban on Japanese travel abroad and limited trade only at the port of Nagasaki with the Chinese and Dutch.