1945


 * The first human-made nuclear weapons are used against an enemy, when the United States drops two atomic bombs on the empire of Japan.
 * The end of World War II, which was one of the bloodiest and most expensive wars in human history up to that point.
 * The United Nations is formed on Earth at the end of World War II. The UN eventually forms the UNSC in the 2100s, but the UN begins embarking on military and security operations as early as the 1950s. Fifty-one nations originally signed the UN Charter, which governed the "global association of governments facilitating co-operation in international law, international security, economic development, and social equity." By the beginning of the 21st century, practically all the nation-states on Earth are members of the United Nations.