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For many who survived the First World War in the 1910s the Second World War of the 1940s seemed eerie deja vu. After a few taut months of conflict it was clear this latest war once more consumed hopes and lives and economies. If that was not bad enough, this new mammoth war no longer entangled troops only within grisly European trenches. Second time around every continent either experienced war on its soil or sent troops to fight on other continents. It was the most cheerless global affirmation of Leon Trotsky’s conclusion that 'you may not be interested in war but war is interested in you'.

Most depressing of all was that military ineptness still flourished in high ranks. While undoubtedly the 1939 blitzkrieg was a striking interservice assault in truth it depended on lack of Polish preparation as much as presence of German preparation. It turned out 500 kg horses were not a serious match to over 50,000 kilogram tanks. Soon after another event stood out and would have changed much had it gone the other way – that is, led to German victory rather than absence of victory. In the summer of 1940 over 300,000 troops seemingly trapped in France escaped to Britain from a minor coastal town called Dunkirk, from there to fight another day (Decisive Day #34, 04/06/1940). It was far from a total escape. Troops discarded large consignments of tanks and other mechanized kit – evacuation priorities was on people – but even what looked like a useful arsenal produced a net loss for Germany. Dunkirk stimulated injections of new and much more modern American material to Britain. Politically, President Roosevelt cajoled Congress to more loosely interpret America’s neutrality policy. From now on, American merchant ships armed themselves and entered European territorial waters officially. ‘We must be the great arsenal of democracy,’ the American president barked in December or 1940, six months after Dunkirk. The British Prime Minister purred in the following February of 1941: ‘Give us the tools and we will finish the job.’ A German U-boat sinking of an American destroyer, the Reuben James, in October 1941 destined the Neutrality Act of 1935 for the dustbin. Cementing Anglo-American connections came the Atlantic Charter. Formally raising a respect to ‘the right of all peoples to choose the form of government under which they will live; and they wish to see sovereign rights and self-government restored to those who have been forcibly deprived of them.’ While Churchill hoped, and said as forcefully as diplomacy allowed, this meant Europe under Nazism, and sometimes Roosevelt approved in polite conversation, in many American minds it also meant colonies under European imperialists. But that divergence was for another day.

More pressing was preventing Germany chasing retreating troops all the way to London. Again, military ineptness thrived. Soon after Dunkirk in the autumn of 1940 came another German fluff that cost the Fatherland dear, when the Luftwaffe conceded it had lost the Battle of Britain (Decisive Day #35, 15/09/1940). More shrewdly manoeuvered and German fighters, battle-hardened in Spain and Poland and the Low Countries, could have presided over the greener Royal Air Force. For some time after as land war occupied politics few spotted the true significance of air power. But in 1945 Prime Minister Atlee noted, surveying what had happened in the six vicious years since German invasion of Poland that Britain’s place in the world had changed: ‘The British Commonwealth and Empire is not a unit that can be defended by itself. It was the creation of a sea power. With the advent of air warfare the conditions which made it possible to defend a string of possessions scattered over five continents by means of a Fleet based on island fortresses have gone.’

Meanwhile in Asia yet more military miscalculations supported Humphrey Bogart's quote from a film of the time (Casablanca, released in 1942) that matters are rarely so bad somebody can't worsen them. Japan had long held imperial ambitions. Sensing weakeness in European powers distracted by turmoil at home and stretched navally she attacked a brace of targets in Asia one weekend in early December. Rounded up in the unusual list of targets, and by far their most significant strike, was against the United States Pacific Fleet moored at Pearl Harbour in Hawaii (Decisive Day #36, 07/12/1941). Military benefits perhaps on paper looked significant but in reality proved momentary. Politically it became a huge Japanese defeat as American isolationism ended decisively. Within four years American garrisons policed not only in the heart of Tokyo but also in much of the East Asian Co-Prosperity scheme that Japan once viewed as their Empire, plus Berlin and across much of the world.

Despite Japanese aggression in Asia and German onslaught against Europe compromise may still have been possible. In the rapidly worsening climate of war some in Britain might just have accepted, as France did, a pro-Nazi, or at least acquiescent, government. But hopes for such accommodation faded when the Vichy government surrendered to Germany the balance of France and French colonies in the autumn of 1942 (Decisive Day #37, 11/11/1942). Large numbers of German troops moved to the Eastern front to defeat, or at least humble, the still fragile Red Army of the Soviet Union, or so the Fuhrer thought.

Sucked into digesting and later at least deflecting the Russian bear Germany overlooked scientific wins. So while the Axis powers, mostly Germany and Japan, often reached critical innovations first like crewless rockets that could bomb distant civilian populations and jet fighter planes that could outperform allied equivalents. But they failed to make them count strategically. America hogged the strategic innovations needed to create and controlling atomic energy through nuclear fission. Critically when this happened in late 1942 (Decisive Day #38, 02/12/1942) it was not by boffins in a Berlin or Munich laboratory but alongside a football stand in Chicago.

Close to Dunkirk the Germans made another crucial military miscalculation when allied troops returned to the continent. Following D-Day in the summer of 1944 (Decisive Day #39, 06/06/1944) they held back important mechanized power that could have delayed the Allied invasion if not denied a beachhead altogether. With allied presence now bedding in on the west of Europe Germany descended into a two-front war they had feared since the 1870s. Alarmed to distraction they injected too much hope into new weaponry. German advances in missiles may have out-paced the world in the early years of World War Two. In the autumn of 1942 they made a first missile which broke the sound barrier. In response the USAF Eighth Air Force had imposed unrelenting raids. With developments came a name change to ‘Vengeance Weapon’ (Decisive Day #40, 08/09/1944).

Not all military ham-fisted lay on one side. Pensiveness and miscalculations in the land invasion of Europe slowed Allied progress. With a bridgehead firmly fixed at Cherbourg, deep in the west of France views differed on how to convert that base into projected power. In the end most of the British view won, to head north and east, rather than the American view to head more directly east. Operation Market Garden, the British initiative to advance through the northern border of Germany may have made sense on paper, much like the Japanese attack on Pearl Harbour was theoretically eye-catching. It’s practical failure in the autumn of 1944 (Decisive Day #41, 18/09/1944) hiccupped the Allied advance towards the fetid Fatherland. By far the most galling and significant effect was that in the following spring it was Soviet Army troops that struck the final blow in the German capital, Berlin. It was not an Allied Army led by the UK and US (Decisive Day #42, 22/04/1945) and the skirl of bagpipes marching underneath the Brandenburg Gate. Had pro-capitalist forces reached Berlin first, the painful and protracted division of Germany into a pro-Communist East and pro-Capitalist West, and indeed Europe into a socialist East and democratic West, might have otherwise been different.

The Russian win in Berlin defined largely the post-war tone of Europe. Even though sometimes the lion has to lie down with lamb, as Churchill once justified supporting Stalin, by the summer of 1945 many saw deep in Russia and the wider USSR the evil temperament of a true despot. Shortly before exiting the mortal coil Trotsky reflected on tussles with Stalin thus: ‘Of Christ’s twelve Apostles, Judas alone proved to be traitor. But if he had acquired power, he would have represented the other eleven Apostles as traitors.’ In part this had roots in the 1940 assassination of exiled Russian revolutionary Leon Trotsky in Mexico City, in the well-known ice-axing by Ramon Mercader. Tension did not ease after Mr Mercader left Mexican prison in 1960. Free to travel the assassin divided life’s remaining days between Cuba and Russia where Khrushchev made him a Hero of the Soviet Union. Trotsky meanwhile found immortality in George Orwell's Animal Farm, published in 1945, reincarnated as Snowball The Pig’. George Orwell’s other classic novel, 1984, satirizing the abuse of power by manipulative double-speaks published in the summer of 1949. Such views became axiomatic in political circles and in 1948 the US Ambassador in London told Churchill ‘the only vocabulary they understand is the vocabulary of force’.

Fortunately war was not all the 1940s symbolized. One of several positives from the struggle was a new international order centred on invigorated respect for the sovereign state – and the end of colonization – and connected by a fresh coterie of institutions. Chief among these loose-knit and interstate organizations was the United Nations which appeared from the frayed remnants of the League of Nations shortly after the end of war in Europe (Decisive Day #43, 26/06/1945). The UN helped set the tone for decolonization and fresh beginnings that characterized the rest of the twentieth century. Discovery of Nazi concentration camps across Europe invigorated the UN mission. Red Army troops discovered Auschwitz in late January and two dozen more in the following months. On the American side, Buchenwald was the first discovery followed by Dachau in southern Germany and a handful more grisly discoveries. American responses were more direct. Troops in selected cities forced German citizens to visit camps and dig graves. But even Soviet troops, no strangers to punishment camps and genocide, felt appalled at the level to which German troops had stooped.

Atomic weaponry had made much advances following Albert Einstein’s communication of the technology and the first practical harvesting of the power in a laboratory. After completion of an unholy trinity of advances – knowledge, test, use – came the first explosions of atomic bombs in Japan (Decisive Day #44, 06/08/1945). Large strands of American society loathed the destructive power but so too did Asians including the jumpy Chinese. Sino-Japanese relations had been tense since 1895 and the seizure of Taiwan. Never fond of their larger and often thuggish neighbour in 1895 a Japanese soldier recorded impressions following a kerfuffle on the large mainland: ‘The faces of the people look human but their custom and spirit are like those of apes. If you showed them in Japan, you would charge an admission fee.’ Such racial undercurrents marred matters between the nations. But with the bombing and the end of the Japaens war – Japan surrendered nine days after the first bomb – history and geography combined to throw Japan and China into a more equal if unpleasant embrace. In 1917, Arthur Balfour, British foreign secretary, said it was folly to forbid Japan some expansion in China: ‘A nation of that sort must have a safety-valve somewhere.’ Now the peace imposed questions arose over what safety valve the Japanese might found – and it turned out to be commerce, which for the remaining decades of the century defined Japan.

Almost immediately after the firestorm ended the colonial unravelling started. On August 17 of 1945, just two days after Japan surrendered, Indonesia declared independence from Holland. Instantly many other colonies looked to their own future with independence more in mind than reunion with former colonial powers. The most pivotal and largest colony was British withdrawal from India in clipped circumstances (Decisive Day #45, 15/08/1947). A series of others arose, prompting some views the whole world was in such extensive upheaval it would be unrecognizable a decade after the war ended. King Farouk of Egypt commented in 1948, half in admiration and half apprehensively: ‘The whole world is in revolt. Soon there will be only five Kings left – the King of England, the King of Spades, The King of Clubs, the King of Hearts, and the King of Diamonds.’

Meanwhile in America advances continued with powered flight. During the war most technologies advanced and notably in powerful hydraulics to help control ever-larger craft and navigation. But these were mostly fine-tunings of known techniques rather than exciting new conquests. Speed was by far the more important and specifically breaking the sound barrier on the west coast of America (Decisive Day #46, 14/10/1947). The news did not happen at times of complete national harmony. The Supreme Court ruled in Hansberry v Lee that whites cannot bar African-Americans from white neighbourhoods. But it did capture the optimistic mood and attraction to breakthrough scientific advance. Added to new lifestyle changes like the new Billboard magazine music best-seller charts American felt modern and vibrant compared to the tired and fractious Europe.

Big changes also appeared in American public life around policing and intelligence gathering. Modern police forces first appeared on the streets of the City of London in Britain in 1829 – modern due to central funding through taxation – and by the mid twentieth-century influenced most urban communities. However the war exposed strategic defects. Keeping order within cities was one matter but understanding the larger world was another. Across all the world new intelligence organizations appeared or old ones invigorated. More important of these was the CIA, set up by the National Security Act of 1947 as initially the Central Intelligence Group. The intent was a foreign-oriented parallel to the domestic-oriented Federal Bureau of Investigation that formed in 1908. Under long-reigned J Edgar Hoover, in charge from 1924 until 1972, just two years short of half-a-century, the FBI carved a central niche in domestic affairs. The CIA sought an equally central slot in foreign affairs. To secure this slice of power the new CIA could use confidential fiscal and administrative procedures and exempting it from many of the usual limits on the use of federal funds. The act also exempted the CIA from having to disclose its ‘organization, functions, officials, titles, salaries, or numbers of personnel employed.’ The Virginia farmboys, one of several monikers reflecting its headquarters location, could also handle defectors and other aliens outside normal immigration procedures.

The CIA helped ferment deep-seated Americans frustration with Soviet militarism. Not that America overlooked Europe. Connection with Europe also developed a prominent mark on history of the two continents. America meanwhile ploughed possessions and cash into exhausted, enervated, and emetic Europe. Grouped under the Marshall Plan this injected what America could provide. General Marshall characterized the effort thus in 1947: ‘Our policy is directed not against any country or doctrine but against hunger, poverty, desperation and chaos. Its purpose should be the revival of a working economy in the world so as to permit the emergence of political and social conditions in which free institutions can exist.’ American administrations determined to follow through on wartime commitments to Judaism spanning back to the Balfour Declaration of 1917. As the and Jewish immigration into Palestine continued this led to one of the most pivotal turning points around Israel – founding the modern state (Decisive Day #47, 14/05/1948). The American push was not only economic and social. It also advanced military fronts too. The North Atlantic Treaty surfaced in 1949, founded on mutual defence where signatories ‘agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all.’ Signed by Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, The Netherlands, Norway, Portugal, and the United Kingdom and the United States

Rounding off post-war changes within societies many societies changed their form of government – starting most memorably with Britain which ditched its firebrand conservative wartime leader for more socialist colour. A homily for freedom, some said. Wining the war was, despite everything, about securing freedom to choose or ditch leaders. Some changes happened peacefully and gradually like Britain’s feisty but non-violent election though many other transformations involved conflict and often outright civil war. By far the most pivotal of the changes happened on the Asian side of the northern hemisphere. Briefly the Japanese surrender had reignited China’s internal tussle but in a short few years Communists had amassed enough power and support to defeat Nationalists. Announcing the People's Republic of China in Beijing in the autumn of 1949 (Decisive Day #48, 01/10/1949). Mao Ze-dong had several political ambitions that looked starry-eyed. Time was to show the fatal results of miscalculations. But in 1949 the key point was that gradualism had no place. Decisively shifted into centrally planned economics was another fifth of humanity. The shift came to define geopolitical balance for the coming decades.