World War III (WWIII or Third World War) is a hypothetical conflict that denotes a successor to World War II (1939–1945). The conflict would be on a global scale, with common speculation that it would likely be a nuclear war and devastating in nature.

In the wake of World War I, World War II, the commencement of the Cold War and the development, testing and use of nuclear weapons, there was early widespread speculation as to the next global war. This war was anticipated and planned for by military and civil authorities, and explored in fiction in many countries. Concepts ranged from the limited use of atomic weapons, to the destruction of the planet.

Norman Podhoretz in his World War IV: The Long Struggle Against Islamofascism has suggested that the Cold War can be identified as World War III because it was fought, although by proxy, on a global scale, with the main combatants, the United States and later NATO, and the Soviet Union and Warsaw Pact countries providing political, military and economic support while not engaging in direct combat. Eliot Cohen, the director of strategic studies at the Paul H. Nitze School of Advanced International Studies at Johns Hopkins University, declared in the Wall Street Journal, a little more than a month after the attacks on the twin towers and the Pentagon, that the struggle against terrorism was more than a law-enforcement operation, and would require military conflict beyond the invasion of Afghanistan. Cohen, like Marenches, considered World War III to be history. "A less palatable but more accurate name is World War IV," he wrote. "The Cold War was World War III, which reminds us that not all global conflicts entail the movement of multi-million-man armies, or conventional front lines on a map." In a 2006 interview, U.S. President George W. Bush labeled the ongoing War on Terror as "World War III" also.

The term Third World arose during the Cold War to define countries that remained non-aligned with either capitalism and NATO (which along with its allies represented the First World), or communism and the Soviet Union (which along with its allies represented the Second World). This definition provided a way of broadly categorizing the nations of the earth into three groups based on social, political, and economic divisions. Due to many of the Third World countries being extremely poor, it became a stereotype such that people commonly refer to undeveloped countries as "third world countries," often used in a pejorative way. Over the last few decades, the term 'Third World' has been used interchangeably with the Global South and Developing Countries to describe poorer countries that have struggled to attain steady economic development. Third World countries includes most of Africa, Latin America, and Asia.

The Third World has also been connected to the world economic division as "periphery" countries in the world system that is dominated by the "core" countries. Due to the complex history of evolving meanings and contexts, there is no clear or agreed upon definition of the Third World and the term is now less popular than it was during the 1970s and 1980s.

David Vaughan Icke (pronounced /aɪk/, or IKE, born 29 April 1952) is an English writer and public speaker, best known for his views on what he calls "who and what is really controlling the world." Describing himself as the most controversial speaker in the world, he is the author of 19 books and has attracted a global following that cuts across the political spectrum. His 533-page The Biggest Secret (1999) has been called "the Rosetta Stone for conspiracy junkies."

Icke was a well-known BBC television sports presenter and spokesman for the Green Party, when in 1990 a psychic told him he was a healer who had been placed on Earth for a purpose, and that the spirit world was going to pass messages to him so he could educate others. In March 1991 he held a press conference to announce that he was a "Son of the Godhead" – a phrase he said later the media had misunderstood – and the following month told the BBC's Terry Wogan show that the world would soon be devastated by tidal waves and earthquakes. He said the show changed his life, turning him from a respected household name into someone who was laughed at whenever he appeared in public.