Defence (military) in the context of "Tank"

National security, or national defence (national defense in American English), is the security and defence of a sovereign state, including its citizens, economy, and institutions, which is regarded as a duty of government. Originally conceived as protection against military attack, national security is widely understood to include also non-military dimensions, such as the security from terrorism, minimization of crime, economic security, energy security, environmental security, food security, and cyber-security. Similarly, national security risks include, in addition to the actions of other states, action by violent non-state actors, by narcotic cartels, organized crime, by multinational corporations, and also the effects of natural disasters.

Governments rely on a range of measures, including political, economic, and military power, as well as diplomacy, to safeguard the security of a state. They may also act to build the conditions of security regionally and internationally by reducing transnational causes of insecurity, such as climate change, economic inequality, political exclusion, and nuclear proliferation.

A moat is a deep, broad ditch dug around a castle, fortification, building, or town, historically to provide it with a preliminary line of defence. Moats can be dry or filled with water. In some places, moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices. In older fortifications, such as hillforts, they are usually referred to simply as ditches, although the function is similar. In later periods, moats or water defences may be largely ornamental. They could also act as a sewer.

Atlanticism, also known as Transatlanticism or North Atlanticism, is the ideology which advocates a close alliance between nations in Northern America (the United States and Canada) and in Europe on political, economic, and defense issues. The term derives from the North Atlantic Ocean, which is bordered by North America and Europe. It is a geopolitical ideology in the same regard as Eurasianism or Gulfism.

The term can be used in a more specific way to refer to support for North Atlantic military alliances against the Soviet Union, or in a more expansive way to imply broader cooperation, perceived deeply shared values, a merging of diplomatic cultures, as well as a sense of community and some degree of integration between North America and Europe. In practice, the philosophy of Atlanticism encourages active North American, particularly American, engagement in Europe and close cooperation between states on both sides of the ocean. Atlanticism manifested itself most strongly during the Second World War and in its aftermath, the Cold War, through the establishment of various Euro-Atlantic institutions, most importantly NATO and the Marshall Plan, with the purpose being to maintain or increase the security and prosperity of the participating countries during the Cold War and protect liberal democracy.