Perry’s arrival in Japan was important for Japan and the world both in the short term and in the long term.
In the short term, Perry’s arrival had a tremendous impact on Japan. Perry’s ability to force the shogunate to do what he wanted showed just how weak Japan was when compared to the Western world. This led rather directly to the reforms that we now know as the Meiji Restoration. This modernized Japan in its economy, its military, its government and its society. Just as one example of how important this was, it ended the division of Japanese society into samurai and commoners.
In the long term, Perry’s arrival impacted both Japan and the rest of the world. Japan’s modernization made it an important power in the world. By 1905, Japan had defeated Russia in a war. In a few more decades, Japan would be able to take on the United States in a tough, though ultimately doomed, war.
Perry’s arrival, then, changed Japan in the short term, thus leading to changes that had a tremendous impact on the world as a whole.