What effect did John Hay's open door policy letters have on the imperial powers of Britain, France, Germany, Russia, and Japan?

It signaled to those powers that the United States would take a larger role in world affairs than before

Explanation:

Open Door policy was initiated by Hay at the end of the 19th century. It addressed the protection of equal privileges and priorities among the countries that traded with China. Being an imperative economic player, Hay thought that China must remain open for equal trade without prioritizing power between states. Hay simply proposed a free market which gave free trading access to foreign merchants that operated in China. He believed that this policy would prevent disputes which threatened state integrity and benefit the US economy as well, resulting in a win-win situation for everyone. He also suggested the Chinese should collect the tariffs from the market