Full list  |  Top Global population: 1.9 billion Olympics: Antwerp, 1920 (2,626 athletes from 29 nations); Paris, 1924 (3,089 athletes from 44 nations); Amsterdam, 1928 (2,883 athletes from 46 nations)

Given the spectacular loss of life during the 1910s it seemed only fair to many the 1920s would be a kinder, gentler time. In several regards the divine pendulum obliged. In industrialized countries the post-war decade became one of psychological rejuvenation, much of which rested on being the right side of the war to end all wars. Jaunty dancing of Fred Astaire and other flappers epitomized the fresh contentment. New leisure pursuits increased too. In 1924 the first crossword puzzle book appeared and in 1929 cartoon strips appeared featuring two heroes handling uppity troublemakers, Buck Rogers, an American adventurer in space, and Tarzan, a more practical English aristocrat marooned in Africa.

The two nascent superpowers were notably big on spin lauding their way of solving life’s ticklish riddles, like how to run decent societies. Stalin saw enough potential in the centrally planned economy of the USSR to boast of at least matching if not surpassing the industrialized economies of America and Europe. Writing in 1929 the hard-nosed dictator predicted: ‘When we have put the USSR in an automobile, and the muzhik [peasant] on a tractor, let the worthy capitalists who boast so loudly of their ‘civilization’ try to overtake us. A couple of years later in 1931 came ambitious talk of slashing the time entailed for overtaking – that, some supporters nervously whispered, or else. ‘We are fifty or a hundred years behind the advanced countries. We must make good this distance in ten years. Either we do it or they crush us.’ America watched the bubbling Soviet optimism cautiously but confidently. President Calvin Coolidge looked at American commercial titans and announced proudly in 1925 that ‘the chief business of the American people is business.’ Americans were already trading around 250 million shares yearly. By the late 1920s this had quadrupled to over a billion shares traded each year. Such growth held its own problems, although invisible in the short run, but for a while it looked ample to outdo any Bolshevik improvements with interest. President Herbert Hoover added to the national sense of satisfaction in 1928: ‘We in America today are nearer to the final triumph over poverty than ever before in the history of any land. The poorhouse is vanishing from among us.’ In such a climate dismissing the claims of a grimmer reality was easy.

Cementing the closeness of America to Europe and chiefly Britain Charles Lindbergh, an American Air Force flyer acting privately, flew solo across the Atlantic in the spring of 1927. Aged only 25 and with a custom-built Ryan monoplane, the Spirit of St Louis, made it without any parachute too. The air-cooled valves had at times brought the flight to as slow as 160 kilometres an hour, but the landing was dramatic enough. After claiming the US$25,000 prize and enduring a brace of parades reflections arose that if conquering the 3,000 km of the Atlantic was feasible, why, it was only 300,000 kilometres or so to reach the moon. Proving just how common Atlantic crossings were in May of 1932 a woman flew from Newfoundland to Ireland. Lindbergh, by the way, had another rippling effect on America. Following abduction and death of a young son a few years later, despite paying a ransom of US$50,000 or twice the prize for crossing the Atlantic, kidnapping changed into a federal rather than state crime. Bruno Hauptmann, arrested for the kidnapping, claimed innocence to the end by electrification.

Within bruised and battered Britain the first socialist government appeared in 1924, a little over five years after the armistice. Closer on paper to the Moscow than to Washington the short-lived episode in time assumed its place as a forerunner to Labour’s three greater wins of 1945 and 1964 and 1997. As examples of its bluntness at transforming industrial relations came the General Strike of 1926. Fired up in early May it fizzled away before the month was out, causing Beatrice Webb to reflect on whether this was a simple chill or outright fever. She wrote contentedly: ‘The failure of the General Strike of 1926 will be one of the most significant landmarks in the history of the British working class. Future historians will, I think, regard it as the death-gasp of that pernicious doctrine of worker’s control of public affairs through the trade unions and by the method of direct action.’ Not just the intelligentsia looked at matters optimistically. George V thought the short-lived General Strike showed what a great and stable political country Britain was. Four million people affected, noted the King, but not a shot fired and no one killed. Winston Churchill, who had witheringly edited the antistrike British Gazette during the turmoil, was more direct in political conclusions. ‘I decline utterly to be impartial as between the fire brigade and the fire,’ the future Prime Minister said. Within a year a Conservative government ruled ‘it shall not be lawful to require any member of a trade union to make any contribution to the political fund of a trade union’. The antiunion legislation stayed in force for two decades until 1946 and the stronger post-war Labour government of Attlee ripped it up.

Woven within this global optimism and uncertain changes in Britain lay increased demand for goods and transport underlined this climate of more optimism. Ever improving technology for the internal-combustion engine looked for new ways to express itself. So of several important moments the most decisive one was opening the first motorway in Germany (Decisive Day #19, 10/09/1921). Shortly after the first autobahn appeared the United States, the United Kingdom and all the other industrialised countries copied the idea. Of all the inventions and innovations of the decade this helped spread the benefits of new science further than might have happened before. The film Metropolis, released in 1927, considered new cities and how autobahns might define them not just on the ground but in the air too.

Underneath sporadic optimism lurked more fundamentally ominous notes. The Ottoman Empire had collapsed to leave a bundle of unstable Muslim and Arab states sitting on large dollops of oil. Coincidentally one of the areas where motorways were rare was Ireland, still tethered umbilically to London. Without efficient transport moving goods and services and, often as important, troops like the recently formed Black and Tans, was difficult. Already Britain had faced down a series of brawls dating from the 1916 Easter Rising. Tension lingered and in 1922 came another example of British weariness when it sliced away 26 counties of Ireland as the Irish Free State. It was not total freedom. A rump British possession of six counties remained in Ulster in the north. And talk of the nearest Dominion to London continued, despite the wishes of firebrand rebels like Michael Collins, and Ireland still swore loyalty to the Crown. Royal Navy ships also continued using Ireland’s Atlantic seaports. But the move was merely a political pause before the final shove. Complete home rule arrived in 1949, not accidentally after yet another large war involving Britain. On the European continent improved road transport helped, in an ironic way, spread a nasty and virulent flu from Asia, which swept not only Europe but Britain and America too. When hygiene and pathogens overcame it, 22 millions were dead, more deaths than the Great War consumed and at the time 1% of the world's population.

As the influenza subsided the first of several changes in post-war European governance happened in the autumn of 1922, three years after Versailles, when Italian fascists secured control of Rome (Decisive Day #20, 30/10/1922). Triggered for one of Europe's great countries was a calamity that spanned two decades and entwined the Mediterranean sphere to the misfortunes of continental Germany. America contained a large Italian population who watched events in Rome closely but distantly, wishing few further entanglements. America had its own concerns, encapsulated most prominently by the temporary insanity of banning alcohol in January of 1920 by the 18th amendment to the US Constitution. American administrators quickly recognized legislating morality was a ticklish matter. ‘The noble experiment’, as its supporters dubbed prohibition, had an ignoble end after dividing the country into sectarian clash between wets and drys. Associated crime and protectionism rocketed with famous names coming to national consciousness such as the Chicago gangster Al Capone. On the other side John D Rockefeller was a famous dry, the boss of Standard Oil, though even the tycoon resigned to the wet view. Paradoxically, wets accepted, the amendment increased alcoholism by glamorizing clandestine drinking and dancing and by some estimates as much as half of all law enforcement went into prohibition cases. Prohibition ended in December of 1933 as the only repealed constitutional amendment, the 21st.

Fundamental as prohibition was America also had a more fundamental and malicious wrestle with racism. In 1922 the Supreme Court outlawed Japanese from naturalized citizenship since they are clearly ‘not Caucasian.’ The ruling was all the more bitter for Takao Ozawa as authorities first denied a citizenship application in 1914, by which time Mr Ozawa had lived in America for twenty years. Graduate from a Berkeley high school and the University of California and on moving to Hawaii an American company employee, attended an American church and sent children to American schools. A Japanese newspaper responded to the ruling with an editorial mourning the shattered hopes for equal treatment.

Shortly afterwards many eyes in not only the scientific world but the political world turned towards Egypt. Announcing the discovery of the tomb of Tutankhamen (Decisive Day #21, 04/11/1922) gave the science of archaeology a dramatic boost. Quickly, the tomb of Tutankhamen became one of the iconic images of the twentieth century. It also became one of the central stories in Britain for a new idea that developed in ways that many countries followed. The British Broadcasting Corporation (Decisive Day #22, 14/11/1922) appeared in London and governments on every settled in continent matched some part of it. Decisively related to this was launching television (Decisive Day #23, 27/01/1926) which helped spread the news from Egypt farther and quicker than goods on the new motorways. John Logie Baird's invention was, at first, wobbly and uncertain and far from convincing. But after 1926 it improved thanks chiefly to American lusts for entertainment and the curiosities of rural communities to see a window on the world. Soon, people were admiring the casket of Tutankhamen from the plains of America to the outback of Australia and the highlands of Scotland, from where the inventor emerged. Fired by prohibition the entertainment industry continued growth. A famous ‘Hollywood’ sign appeared in 1923. Created as a real estate ad it originally read Hollywoodland. The dynamism of Los Angeles was real. Yet, Los Angeles and California have, together, defined in many ways for the modern world just what it means to be accepting of tolerance and difference. America considers LA it’s greatest cities. Hollywood gives Los Angeles a reputation as the entertainment capital of the world. It is little surprise the Olympics have happened here twice, in 1932 and 1984, when America has over a score of cities able to host the Games. Frank Lloyd Wright was a tad unkind, speaking in the 1930s, that ‘Tip the world on its side and everything loose will land in Los Angeles’

Another scientific advance from the 1920s, though one often associated with the forties when it first attracted global prominence, was discovering penicillin in 1928 (Decisive Day #24, 15/09/1928). Alexander Fleming, a Scottish researcher, first stumbled across the microbes punchy enough to save millions of lives by accident. Of all the advances in the 1920s this one stood out for creating something not confined to industrialized and wealthy societies but transferable around the rich and the poor.

More vexing of all post-war American responses came in 1920 when the United States had refused to join the League of Nations. Calvin Coolidge, speaking in 1923, hoped the League would be helpful before adding: ‘But the United States sees no reason to limit its own freedom and independence by joining it.’ Cooperation did exist on other fronts. Interpol, or International Criminal Police Organization, launched as The International Criminal Police Commission in 1923. It adopted its telegraphic address in its name in 1956. Privately, many American senators and congress representatives cheered on initiatives such as the Kellog-Briand pact of 1928, which optimistically sought to outlaw aggressive wars. Although signed by over sixty countries, including all three future Axis countries: Germany, Italy, and Japan, not everyone signed and honoured the thinking. Small countries still existed and many were unstable. Afghanistan, for example, went through three violent changes in government around this era, changing power in 1919 (assassination) and 1929 (abdication) and 1929 (execution). For good measure more coups came in 1933 (assassination), 1973 (deposition), 1978 (execution), 1979 (execution, twice), 1987 (removal), 1992 (overthrow), and 1996 (overthrow). David Lloyd George, speaking in 1919, prophetically underlined fears of countless fragile and unviable countries: ‘It fills me with despair the way in which I have seen small nations, before they have hardly leapt into the light of freedom, beginning to oppress other races than their own.’

During the 1920s other hopeful dictators doubted Lenin’s achievements. Benito Mussolini, writing from Italy in 1920, looked on Lenin not as a statesman but an artist who worked on people like a sculptor. The only problem, of course, was that ‘human beings are harder than granite and less malleable than iron.’ Most of all Lenin failed because the task of moulding people was ‘beyond his powers’. Proof of this impotency existed in the NEP, the New Economic Policy, effectively introducing capitalism into central strands of agricultural production. Lenin also grew cynical. At one point aids found he had scribbled on a paper: ‘Out of every hundred Bolsheviks 70 are fools and 29 rogues, and only one a real socialist.’ The cynicism carried on with prominent revolutionary and philosopher Trotsky who already by 1924 was heaping faint praise on Stalin. ‘He is needed by all of them,’ Trotsky mused, dejectedly and darkly. ‘By the tired radicals, by the bureaucrats, by the nepmen, the kulaks, the upstarts, the sneaks, by all the worms that are crawling out of the upturned soil of the manured revolution.’ Stalin did not take the slur lying down. In 1926 he eased Trotsky from the party. After that Trotsky’s view became even more direct: Stalin was a revolutionary gravedigger, reckoned Stalin’s often angered rival, easily tempted by shootings and mass killings.

The German stock market collapsed under post-war reparations and inflationary pressure in 1922 and the American stock market collapsed from overconfidence in 1929. In the couple of days following Black Thursday (October 24 of 1929) more value evaporated from America’s stock market than America spent fighting and subsidizing World War One. 13 million shares crashed in hours and led within months to the Great Depression, which lasted for much of the early 1930s. Within three years over a quarter of the American workforce – an astonishing 15 millions or one worker in four – considered themselves unemployed or underemployed. Over a third of banks crashed. Guessing the attitude of the many is no sparking science. Keynes penetratingly settled that professional investment was like a surreal beauty contest where the goal was not to choose the most beautiful, but rather to anticipate ‘what average opinion expects the average opinion to be.’