What it is: In a 'cold' war there is tension and hostility but no open warfare, though the weapons of a 'hot' war are kept in readiness. The weapons of a cold war are propaganda, threats of military action (from time to time backed up by displays of military power), economic blockades, and any other ways of creating political and economic difficulties for opponents. There is also the psychological stress caused by uncertainty and fear. 'The Cold War' refers to the years of heavily-armed hostility between the USA (and its allies) in the west and the Soviet Union (and its satellite states) in the east.

Brandenburg Gate

The 'wall' before 1989 encircling West Berlin

What it means: The east-west Cold War began soon after the end of the Second World War, during which most of the countries later involved in the Cold War had fought on the same side (the Allies). The Soviet Union was run by a Communist government, which was keen to spread its influence. America, a capitalist country, deeply distrusted and feared Communism and Communists, and wanted their influence stopped. During the 1980s the new Russian leader, Mikhail Gorbachev, introduced 'glasnost': a more open government and better communication with the West. Countries in the Soviet Union now began to see that communism had failed. Some began thinking about independence. All this helped to end the Cold War. The fall of the Berlin Wall became a symbol of the end of the Cold War era. (Berlin was the capital of what was then East Germany. The Wall was built in 1961 to seal off west Berlin, a land 'island' occupied by Western forces - the USA, UK and France - since 1945. The aim was to prevent illegal emigration from East to West. In 1989, after strong public pressure, the Wall was suddenly opened to traffic, and many people began to demolish it with their bare hands.) In 1991 the Soviet Union collapsed. Though there had been no actual fighting in the Cold War (despite crises that almost led to all-out war), there were losses. Both sides spent billions on increasingly sophisticated weapons, especially nuclear-armed missiles. Both sides took part in 'proxy' wars against each other, by supplying weapons and support to their chosen sides fighting in 'hot' wars in Africa and Asia; many people died. A number of people were shot by East German forces for trying to cross the heavily-guarded frontier between Eastern and Western Europe known as the 'iron curtain'.

Think about it: Most people alive at the beginning of the 21st century had lived through or were born under 'the nuclear threat'. Not many seem to remember or understand the tension that was felt everywhere during the Cold War, especially during the 1960s. Few realise just how close the world was to nuclear devastation. Few think about what small accidents could easily have started it. A message not sent, a message not received, a message misunderstood; one person's decision to disobey orders; the inability of each side to understand the other's motives and ways of thinking; a radio-telephone breakdown; a flight of birds mistaken for missiles. All these things, and many more, almost tipped the world into a new holocaust. It was a matter of pure luck that this didn't happen, helped by one other thing: the private reluctance of the leaders on both sides to use their nuclear weapons. All wars are prone to accidents, and the disorder and confusion of war increases the chances of disaster. Think about narrow escapes in everyday life, from floods and power-cuts down to a personal crisis caused by a carelessly uttered word.  Why do people stack up trouble in the shape of countless weapons as well?