Quick quiz: name the last day to change the world? On what date was the world never quite the same again?

Many will think instinctively of the terrorist attacks against America on September 11, 2001. Though not everyone. Probably some might think of the London bombings on July 7, 2005. Certainly some will see beyond 9/11 or 7/7 and think of, say, the US-led attack against Iraq (March 20, 2003). President Bush’s re-election to a second term in office (November 2, 2004) might also count as a decisive day that changed the world. Without that mandate the American war on terror post-2004 might have been prosecuted differently or even not all.

Within this quick selection there are already obvious differences that illuminate the sorts of questions necessary to rank importance. The terrorist bombings against America in 2001, for example, killed far more people and changed far more western foreign policy than the attacks against Britain in 2005. So which is the more decisive day? 9/11 or 7/7? What sort of rules or at least guidelines might help decide on other decisive days?

Type #1: Transferable
It is helpful to start with an easy conclusion. A ‘decisive day’ is likely to be one that produces outcomes that impact more than its local or regional context. This explains why 9/11 is more prominent in many peoples mind compared to the London bombings of 7/7 – only the former day led to America removing rogue regimes in another continent. Transferable impacts though is not just about politics or war. The start of the BBC (November 14, 1922) was a decisive shift in global communications and entertainment. It may have first happened in Britain but public broadcasting on the British Broadcasting Corporation model impacted many countries around the world. The Canadian and Australian broadcasting corporations were both modeled on the BBC and are two examples of several about how influential the BBC became. Also within the area of communications and entertainment is the creation of Britain’s Sun newspaper (September 14, 1964). That too was a highly transferable turning point. The Sun sparked a tabloid style of journalism that spread globally. By the end of the century most countries in the world produced tabloid newspapers along the lines of The Sun, for good or bad or ugly.  

Type #2: Critical scientific advances
Inevitably science counts too when deciding on what is a decisive turning point from merely a bend in the road. Science impacts most lives on the planet in one way or another and many historical summaries of the twentieth century would consider it a century of science. Well, it was also a century of wars and political fragmentation but science was always there, quietly, steadily, sometimes ruthlessly advancing. As an obvious if ominous example the first controlled use of nuclear fission (December 2, 1942) was an unrivalled scientific breakthrough. The knowledge may have quickly transferred to weaponry in most of the powerful countries but it also transferred to energy creation across less powerful countries too. The invention of the microchip (November 15, 1971) travelled even further than nuclear power by reaching and benefiting billions of people who use computers or whose lives are improved by computers.   

Type #3: Physical conquest
Some days also are decisive because they mark something that humanity never before achieved. Landing on the moon is perhaps the most obvious such moment (July 20, 1969). The successful landing on that summer day represented a one-off milestone that can never happen again. Humanity had asked for the moon for a long, long, time and experienced many advances before then. Each were significant examples of conquest too but it was the first landing of the moon that will forever go down as a significant moment. Before the moon there was breaking the sound barrier (Chuck Yaeger on October 14, 1947) and the first person in space (Yuri Gagarin on April 12, 1961). There was also physical conquest in sport, for example at the 1936 Berlin Olympics when Jesse Owens defeated many athletes from Nazi Germany.

Type #4: Political turning points
Loved or loathed politicians and leaders often define history. Politics remains one of the few professions able to define entire periods so they too are often important when considering a decisive day. Two milestones from the twentieth century jump immediately to mind: the first election of President Franklin Roosevelt (November 8, 1932) in America and the first election of Prime Minister Margaret Thatcher (May 4, 1979) in Britain. Roosevelt's New Deal and Thatcherist privatization may have loitered at opposite ends of the political spectrum, one politically left and one politically right, but each defined a generation in their way. The same applies, though for rather different reasons, of President Nixon’s resignation (August 8, 1974) and the mark this left on American views of itself and of others views of America.

Type #5: Killing of famous individuals – the assassination
Tricky Dicky (one of President Nixon’s nicknames) would doubtless confirm that not everyone leaves high office in quite the fashion they hoped. Another type of event that turns around individuals but can have global impacts is their killing. Assassinating President Kennedy obviously shocked many (November 22, 1963) and for some time anyway turned important strands of American foreign policy. More than the emotional loss, though, was what came afterwards as America under Kennedy's successor turned decisively towards Civil Rights. Rather paradoxically the assassination of President Kennedy also heightened a commitment to a sequence of uncaring administrations and war in South Vietnam. The results of Kennedy’s death cannot compare to the effects of the earlier assassination of Archduke Franz Ferdinand (June 28, 1914), which ignited the First World War across Europe.

Type #6: Killing of unknown masses – war
To paraphrase Trotsky: you might not be interested in war but that’s tough luck for war is interested in you. Look at any century in human history and war is there. The twentieth century was no different and included the double and linked catastrophe of a predominately European First World War and within two decades a truly global Second World War. Events catalyzing these two massive wars were hugely decisive in forming the look-and-feel of the twentieth century. But there was also more geographically limited and shorter wars that still changed the world. Japan’s defeat of Russia (September 5, 1905) is undoubtedly one of the more important ‘minor’ wars. Franco’s victory in the Spanish Civil War (November 28, 1939) and the conquest of Saigon in the Vietnamese Civil War (April 30, 1975) also tilted countries and geopolitical arrangements.   

So, that might be six key guides or rules that can turn an ordinary event into the extraordinary: if the event is transferable; or if there is a critical science advance; or if there is physical conquest; or a political turning point; or the assassination of leaders; or war. At a simple level every decisive event falls into at least one, sometimes more, of those categories. 

From this thinking emerges a selection of decisive days in the twentieth century. It starts with a straightforward but perhaps overlooked one: the launch of the Eastman Kodak Brownie camera (February 8, 1900). This was a highly transferable scientific advance. It ends – where else – with the dramatic political turning point of the Kyoto treaty on climate control. Although the unfortunate and much-maligned treaty only came into force by 2005, eight years afterwards and some way into the twenty-first century, it did first appear on the legislative table during the twentieth century (December 11, 1997).

Sandwiched between the launch of the Kodak Brownie camera and start of the Kyoto Treaty are ninety-eight other decisive days. The sinking of the Titanic, discovery of penicillin, Cuban Missile Crisis, the first test tube baby. They are all there.

What else can we say about a list of a hundred decisive moments? Well, obviously this is a fairly short list. One hundred days is anyway only 0.3% of the 36,500 or so days in the last century. Inevitably the other 99.7% of days also contained some decisive days that influenced the world to some extent. But this list is only a hundred so excluding some is necessary.

A list like this does shed some quantitative light on the often-raised claim that the twentieth-century was a predominately western and especially Anglo-Saxon century. That is fairly reasonable characterization but not a complete summary by any means. About 40% of the decisive moments in this list emerged from Europe. Given Europe is not even one-tenth of the world's population this is notable. More notable is that very often they involved Britain in some form – from British advances in science like inventing penicillin (September 15, 1928) or the first test tube baby (July 25, 1978) to British influence on foreign policy like the Balfour Declaration for a Jewish homeland (November 2, 1917) or withdrawal from an Indea fragmented between Muslim and Hindu (August 15, 1947). But non Anglo-Saxon Scandinavia contributed a little and so did the French, here and there. Gallic surrender to German Nazis (1941) and Vietnamese Communists at Dien Bien Phu (May 8, 1954) irrevocably altered Europe and Asia, for example, though perhaps not quite in the way Paris wished.

But the twentieth century was not just about Europe or about what European powers changed the world overseas. One-third of important moments happened in the Americas and especially the United States. In much the same way as the UK stood influential in Europe so the US stood ascendant in the Americas. A lot of American influence was related to science and especially to exploration – as well as the moon landings there was powered flight (December 14, 1903) and the departure of Mariner 9 from our universe (November 13, 1971). The Americans also had the dubious privilege of resolving not one but two continent-wide wars, entering the First World War in Europe on April 16, 1917 and then leading the invasion of Europe on D-Day, June 6, 1944. Not content with resolving two European wars they also resolved another one in Asia for good measure, marked decisively by the nuclear bombing of Hiroshima on August 6, 1945. That too was a turning point for it introduced a new weapon to humanity. The milestone will forever stand as an American accomplishment, or necessary evil or outright sin according to different views.

What of Asia? Globally decisive days in Asia make up only one–fifth of this Top 100. China takes several of these days, naturally enough, and in particular its decisive ending of decrepit Qing rule in favour of republicanism (January 1, 1912). For good measure the Chinese initiated two more significant revolutions in the century. First in October 1, 1949 when they moved one fifth of humanity into Communist administration and second in January 19, 1992 when they moved them out again and instead into Capitalist administration. In the Communist experiment lasting four decades tens of millions were killed.  

Nietzsche once said that the ‘doer alone learneth’. Within that might be a hopeful message for the twentieth century world. For a lot of doing happened in the twentieth century and if a lot of learning emerges from it then that cannot be too harmful.

Sadly a lot of learning arose from unabashed evil and disdain for fellow humans. At the end of the twentieth century many more people than at the beginning possessed peaceful lives with decent healthcare and education and the chance to hope for better lives for our children. But many did not. In fact most of the people in the world at the end of the twentieth century did not live with much hope. They lived often in desperation and frustration. Two thirds survived on a few dollars a day – less than the cost of a book. Most did not have reliable water. To quote Nietzsche to them, to imply that which does not kill us makes it stronger, would be unfair and condescending. They would not agree. Life for them in 2000 and after a century of one hundred decisive days remains largely as it was in 1900 –  nasty brutish and short.

Recognizing the good and bad in events
So perhaps it is not about what Nietzsche thought but Aristotle. The ancient Greek said ‘If things do not turn out as we wish, we should wish for them as they turn out.’ It is a canny thought. Simply put it reminds us there are times to accept the world as it is. Many examples from the twentieth century bring this more pragmatic observation to life.

September 1, 1939 saw the onset of World War Two and terrible results for Poland and Europe and indeed the world. September 19, 1898, on the other hand, witnessed female suffrage in New Zealand. America and Britain and much of the liberal world followed.

It sounds like one bad and one good event. Or does it? Scratch the surface and these events hold subtler outcomes beyond ‘a bad thing’ and ‘a good thing’. September 1, 1939 was obviously an immediate misfortune for Poland and Europe. Yet, some positive results appeared in the longer run. European colonization with all its mighty iniquities ended much more quickly than if there was no war. Nazi brutality over Poland helped lessen American isolationism, always a prevailing point on Washington’s political compass, and along the way the twin forces of American cash and liberalism transformed Europe and East Asia and other places besides. The state of Israel appeared, or perhaps reappeared according to some views, and whether we think that is good or bad it seems unlikely this would have happened without the tragedy that followed September 1, 1939.

On the first election in America where women had the vote, 1920, the voting constituency theoretically doubled. Did woman voters improve matters? Well, in that election Americans voted in leaders who were against joining the League of Nations. This isolationism captured the American mood until Japan and Germany jolted the sleeping giant awake nearly two decades later. This prompts ticklish questions. What if only men voted in 1920? Would men feel unencumbered by female concerns of sending American sons and husbands to war? If there had been an exclusively male constituency would the world’s newest power have joined the League of Nations? If yes, who knows what might have happened after 1920. The League of Nations with firm American backing might have been strong rather than the hotchpotch of weak alliances into which it degenerated. With American support there might have been firmer global willingness to hold the line against German rearmament and Japanese imperialism? Ultimately, the questions might continue, might World War Two have never happened?  

Other examples are around too. The Treaty of Versailles of 1919, for example, achieved the unique paradox of sterilizing one war but at the same fertilizing the seeds of the Second World War. Such good news then bad news stories do not come much larger than that.

Obviously this doesn't prove a logical point. Yet these examples do remind us that any event always contains the potential for positive and negative outcomes. Put another way nothing leads to all good, alas, but thankfully it is rare to find events leading to all bad. In short, it pays to consider Decisive Days as neither about glasses that are half full or glasses that are half-empty, it is just about the glass.