How was us economic policy toward japan and china similar during the 19th century?

They worked to open both countries to foreign trade.

Explanation:

During the nineteenth century, the United States, China and Japan underwent a series of transformations. Perhaps the most important of these transformations has been the opening of these countries to foreign trade. At that time, the US was beginning to prepare its influence on trade relations with other cultures.

At the same time, Western countries forced Japan to open trade. Japan implemented a modernization (Meiji Restoration), seeing China as an antiquated civilization, unable to defend itself against Western forces partly due to the Opium Wars and the Anglo-French Expeditions from 1840 to 1860.

After the Opium War, China realized that other cultures had customs - such as diplomacy - different from their own, as well as material capabilities larger than theirs, with steam ships and well developed firearms. This period is known to the Chinese as the "Century of Humiliation," when the European countries and Japan greatly influenced the policy of the Chinese Empire and took advantage of the Uneven Agreements.  After decades of internal turmoil in 1949, the Chinese Communist Party took control of Mainland China and thus changed China's foreign policy to combat US imperialism. This approach was abandoned in the 1960s and 1970s, after the ideological separation of the Soviet Union, the other communist power, and the rapprochement with the United States. With the government of Deng Xiao Ping and the process of economic opening, the country became more dependent on capitalist economies and thus stopped making stronger opposition to countries for ideological reasons.

basic principles: federalism, separation of powers, checks and balances, judicial review, representative democracy, limited government, rule of law, individual rights and responsibilities, consent of the governed, majority rule, popular sovereignty, equal protection.

the anwser is a) to prevent military conflict