The United States of America (USA), commonly referred to as the United States (US), America, or simply the States, is a federal republic consisting of 50 states, 16 territories, a federal district, and various overseas extraterritorial jurisdictions. The 48 contiguous states and the federal district of Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is the northwestern part of North America and the state of Hawaii is an archipelago in the mid-Pacific. The country also has five populated and nine unpopulated territories in the Pacific and the Caribbean. At 3.79 million square miles (9.83 million km2) in total and with around 316 million people, the United States is the fourth-largest country by total area and third largest by population. It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The geography and climate of the United States is also extremely diverse, and it is home to a wide variety of wildlife.
Paleo-indians migrated from Asia to what is now the US mainland around 15,000 years ago, with European colonization beginning in the 16th century. The United States emerged from 13 British colonies located along the Atlantic seaboard. Disputes between Great Britain and these colonies led to the American Revolution. On July 4, 1776, delegates from the 13 colonies unanimously issued the Declaration of Independence. The ensuing war ended in 1783 with the recognition of independence of the United States from the Kingdom of Great Britain, and was the first successful war of independence against a European colonial empire. The current Constitution was adopted on September 17, 1787. The first 10 amendments, collectively named the Bill of Rights, were ratified in 1791 and guarantee many fundamental civil rights and freedoms.
Political geography is the field of human geography that is concerned with the study of both the spatially uneven outcomes of political processes and the ways in which political processes are themselves affected by spatial structures. Conventionally political geography adopts a three-scale structure for the purposes of analysis with the study of the state at the centre, above this is the study of international relations (or geopolitics), and below it is the study of localities. The primary concerns of the sub-discipline can be summarised as the inter-relationships between people, state, and territory.
"Political geography in essence builds a country economy" The origins of political geography lie in the origins of human geography itself and the early practitioners were concerned mainly with the military and political consequences of the relationships between physical geography, state territories, and state power. In particular there was a close association with regional geography, with its focus on the unique characteristics of regions, and environmental determinism with its emphasis on the influence of the physical environment on human activities. This association found expression in the work of the German geographer Friedrich Ratzel who, in 1897 in his book Politische Geographie, developed the concept of Lebensraum (living space) which explicitly linked the cultural growth of a nation with territorial expansion, and which was later used to provide academic legitimation for the imperialist expansion of the German Third Reich in the 1930s.
There are 193 United Nations (UN) member states, and each of them is a member of the United Nations General Assembly.
The criteria for admission of new members are set out in the United Nations Charter, Chapter II, Article 4:
Martial law is the imposition of military rule by military authorities over designated regions on an emergency basis.
Martial law is usually imposed on a temporary basis when the civilian government or civilian authorities fail to function effectively (e.g., maintain order and security, or provide essential services), when there are extensive riots and protests, or when the disobedience of the law becomes widespread. Fundamentally it is a requirement put on civilian government when they fail to function correctly.
Military justice is the body of laws and procedures governing members of the armed forces. Many states have separate and distinct bodies of law that govern the conduct of members of their armed forces. Some states use special judicial and other arrangements to enforce those laws, while others use civilian judicial systems. Legal issues unique to military justice include the preservation of good order and discipline, the legality of orders, and appropriate conduct for members of the military. Some states enable their military justice systems to deal with civil offenses committed by their armed forces in some circumstances.
Military justice is distinct from the imposition of military authority on a civilian population as a substitute for civil authority. The latter condition is generally termed martial law, and is often declared in times of emergency, war, or civil unrest. Most countries restrict when and in what manner martial law may be declared and enforced.