The term yellow peril was coined by a German emperor in 1895.

"The term Yellow Peril was coined by German Emperor Wilhelm II in 1895, but the theory that Asian peoples represented a menace to the West originated in the late nineteenth century with Chinese immigrants as coolie slaves or laborers to various Western countries, notably the United States. It was later associated with the Japanese during the mid-20th century, due to Japanese military expansion, and eventually extended to all Asians of East and Southeast Asian descent."

"The term refers to perceptions regarding the skin color of East Asians, the fear that the mass immigration of Asians threatened white wages and standards of living, the fear that Asians had some sort of unnatural sexuality that threatened Western women with rape and the fear that they would eventually take over and destroy western civilization, replacing it with their ways of life and values."

Check "yellow peril" from Wiki.