In September 1939 the most destructive war the world has ever known began as German troops invaded Poland. Yet, barely 20 years earlier, jubilant crowds in Britain, France and the USA had been told that they had won the war to end all wars. Contempt for their weakness now led Hitler to make a series of land grabs which brought Europe to the brink of war. When they finally reacted, it was too late.

Hitler’s forces took just four weeks to conquer Poland. Poland was not only outnumbered both in men and weapons, but facing a new type of warfare – Lightning War or Blitzkrieg – for which it was totally unprepared. When Hitler attached the west in May 1940, the result was just as devastating. Within four weeks the British army was forced out of mainland Europe, and France totally occupied.

By the end of June 1940, Hitler was victorious in western Europe. Nazi Germany now controlled Denmark, Norway, the Netherlands, Belgium and France … only Britain remained defiant. Once Britain’s survival had been ensured by a narrow victory, Churchill could begin the work of forming a grand alliance against Nazism and beginning the fight back in occupied Europe.

By the autumn of 1940, Hitler’s forces were supreme in Western Europe. Britain alone remained undefeated but Hitler no longer considered it a problem. The German Fuhrer was ready for his greatest gamble – Operation Barbarossa, the assault on his arch-enemy, the massive Soviet Union, in the summer of 1941. After months of savage hand-to-hand fighting a German army was cut off and annihilated.

On December 7th 1941, World War 2 changed dramatically as Japanese planes swooped in for a surprise attack on the US Pacific Fleet in Pearl Harbor. A conflict that had been fought almost entirely in Europe was now to be fought worldwide, for two days later Hitler also declared war on America. The US immediately mobilized its enormous strength and began to fight back.

Italy’s dictator Benito Mussolini dreamt of recreating the Roman Empire. In September 1940 his armies advanced into Egypt and opened up a completely new theatre of World War II. The British were outnumbered, and Mussolini’s victory should have been a walkover. But the British had other ideas and the Italians were soon being pushed back hundreds of miles.

As the War continued, there was a race to develop new ways to wage war. Both the Allies and Germans were searching for something that would give them a knock-out blow and bring the war to a quick end. In Britain and America there was growing interest in strategic bombing, but this strategy would take an horrific toll on human life, and eventually lead to a bitter controversy which continues today.

By mid-1943, Hitler was on the run. The reality of a war on two fronts had caught up with him. In the West, an Allied assault on Italy threatened his southern flank. In the East, exhausted German troops were fighting against the enormous reserves of the Soviet military machine. By the end of the year the foundations of the future Soviet bloc had been laid.

By early 1944 Hitler faced a new threat. In the West, Allied preparations to invade north-west France were coming to a climax. When Operation Overlord did come, the first troops successfully breached Hitler’s Atlantic Wall and established a firm beachhead. Less than two months after the landings, after British attacks had pinned down the German Panzers, US forces led a breakout from Normandy.

By late summer 1944 the Allied forces in north-west Europe were thrusting towards the German border. Paris and Antwerp were liberated, but then supply problems brought the advance to a halt. Meanwhile on the eastern front the real horror of the Nazi Regime was beginning to emerge with the discovery of the first death camps and the reality of Hitler’s determination to exterminate the Jews.

By spring 1943 the Pacific war had reached a turning point. The United States had stopped the Japanese advance, now it launched a two-pronged attack to drive it back. As their situation became ever more desperate, the Japanese turned to Kamikaze suicide units to stem the enemy advance. But nothing they could do, could prevent inevitable crushing defeat.

As 1945 began, Hitler’s Third Reich was entering its death throes. In the west, Allied forces were within striking distance of the Rhine. In the east, a Red Army blitzkrieg brought Soviet forces just an hour’s drive from Berlin. The final cataclysmic battle to capture Berlin began on April 16th. Nine days later, the city was surrounded, and Soviet troops eliminated the last Nazi resistance.

As the Allies reached the Japanese home islands they faced a dreadful problem. How could they force such a determined enemy to capitulate without the inevitable and massive casualties which an invasion must result in? It would lead them to employ a new weapon so dreadful that even the Japanese were forced to surrender, a weapon that would have profound consequences for the future of mankind.