A look at the oil industry in the years following the World War Two, in particular, the challenges the "majors" faced from the countries whose oil they had exploited. Key events in this turbulent period include Iran's nationalisation of oil output in 1951, and Egypt's blockade of the Suez Canal which restricted the delivery of oil to Europe in 1956. This is the second part of a five part series looking at oil from its beginnings in Pennsylvania, USA in 1859, to the days following WWII