A. Developed as a result of the tensions between the US and Soviet Union
The security measures being referred to in Korematsu v. United States were the internment of Japanese Americans, ordered by the Executive Order 9066.
The Executive Order 9066, issued on February 19, 1942 by the 32nd President of the United States of America Franklin Delano Roosevelt, decreed that all residents of the United States of Japanese, German, and Italian origin, even if born in American territory, should be locked up in a concentration camp.
A total of 110,000 Japanese Americans were interned. One of the most important camps was in Manzanar, which stood in a valley between Los Angeles and San Francisco.
During the First Opium War the British dominated the Chinese and defeated them relatively easily, despite being heavily outnumbered. The reasons for this were that the British had modern and very well equipped army, while the Chinese had old equipment which was also not in sufficient amount, were not well organized, and also big portion of the fighters were not professional military but peasants. China had big internal problems as well, so the nation was united, which shrunk its chances of defeating the British.