In the summer of 1940, Great Britain is under attack in the air and at sea. German U-Boat wolf packs prowl the Atlantic and sink over a million tons of shipping. German skippers call this the “happy time” — but was the German Navy actually that successful early in the Battle of the Atlantic?

The Russian Federation is at war with Ukraine, and some of its supporters insist it will win because Russia doesn’t lose wars. They point to its vast territory, its cold climate, its manpower reserves, or its people’s ability to endure hardship and accept death – and they point to great Russian victories of the past. So let’s put this claim to the test and see what history has to say about Russia’s record on the battlefield.

With the Japanese surrender in September 1945, the Second World War comes to an end. But for China there won't be peace right away because the nationalists under Chiang Kai-Shek and the communists under Mao Zedong still haven't resolved their struggle and so the Chinese Civil War will flare up once again.

The Battle of Norway in Spring 1940 cemented the reputation of the daring and invincible German war machine under Adolf Hitler. But while Denmark and Norway were successfully occupied by Germany, the campaign came at a heavy cost. This was especially true for the German Kriegsmarine which lost a significant amount of warships including the Blücher - losses that essentially crippled them for the remainder of the war.

In September 1980, Iraq invades Iran. Iraqi leader Saddam Hussein is convinced that now is the time to strike, since Iran is still shaken by its Islamic Revolution, and he expects victory within weeks. Instead, the conflict will last 8 years, cost hundreds of thousands of lives , threaten world oil markets, and draw the US into the Persian Gulf for good. It’s the last total war of the 20th century.

Hitler's victories in 1940 present a historic opportunity to Italian Dictator Benito Mussolini to expand the Italian Empire. Instead, Italy suffers a series of humiliating disasters in Greece and North Africa. So why did Mussolini declare war on the Allies at this moment, and could Germany be ultimately responsible for the Italian fiasco?

In 1894, tensions are rising in East Asia. There’s trouble in the small but strategically-located Kingdom of Korea, as rival factions in the royal family fight for power and against popular uprisings. Shaken by a major revolt, Korea’s King Kojong calls on China for help – but Japan intervenes, setting off a war that will devastate Korea and upend the old order in Asia.

In the early 19th century, the United States and Mexico share a massive cross- continental border, but US settlement in Mexico, expansionist ideals and religious differences put the young republics on a collision course. As tensions boil over into bloodshed, the tiny, inexperienced US army marches to a war which will forge the modern United States.

On October 6, 1973, Israelis celebrating the holiday of Yom Kippur are shocked by news of a mass two front attack in the Sinai and Golan Heights. Egypt and Syria, two nations still reeling from their humiliating defeat by Israel in 1967, smash through Israeli defenses.

On September 1, 1939, Germany invades Poland, setting off the Second World War. Two days later, Britain and France declare war on Germany. As the German army races towards Warsaw, many German generals are worried the French might simply walk into western Germany, and there’s not much the Wehrmacht can do about if they do. But instead of a powerful Allied counteroffensive, the French and British mostly sit back and wait during the so-called Phoney War – so why didn’t the Allies attack Germany in 1939?

In the summer of 1940, the British Empire faces German attacks against the home islands a new Italian adversary in the Mediterranean Sea, the lifeline to its colonies around the globe. In a series of campaigns the British beat back the Italians and eliminate parts of the French fleet. But the service of its overseas subjects won't come for free.

In September 1944, the US 1st Marine Division is on its way to another amphibious invasion in the Pacific – the tiny island of Peleliu. For almost half the Marines it will be their baptism of fire against veteran Japanese troops with a new defensive doctrine. Some American commanders call for the operation to be cancelled, but it goes ahead. By its end, half the Marines and all the Japanese will be killed or wounded – but was Peleliu worth it?

Germany and the Soviet Union both regarded the Polish state as a creation of the post-WW1 system, and both had claims on Polish territory. In the summer of 1939, Adolf Hitler decided to invade Poland in a fait acompli against the Allies. In a secret agreement between Germany and the Soviet Union they agreed on dividing up the Polish state and Eastern Europe.

China was constantly at war from the late 1920s to the early 1950s, including becoming one of the largest fronts of the Second World War. The Japanese invasion and followed by the resumption of the Chinese Civil War between nationalists and communists would have huge global ramifications. But to understand how the wars for China began, we need to go a little further back to a time of great Chinese vulnerability.

In Fall 1944, Japan is set on stopping the US from re-capturing the Philippines, a vital trade route between the Japanese home islands and the resource rich occupied territories to the south. With a complex plan they want to strike the US Navy as it's landing on Leyte island. The resulting series of battles is today known as the Battle of Leyte Gulf, the biggest naval battle in history.

The Battle of Manila 1945 was the only urban battle in the American Pacific War comparable with Stalingrad, Berlin or other European battles. In gruelling weeks of fighting the 6th Army fought in house-to-house combat against entrenched Japanese.

Christmas 1979. Soviet armor pours across the Afghan border towards Kabul as helicopters secure the mountain passes through the Hindukush mountains. In Moscow, the Politburo has decided to save Afghanistan’s communist government from collapse. Afghan rebels have taken up arms against the unpopular regime and control most of the countryside. But the Red Army leadership doubts it can pacify the country - so why did the Soviet Union invade Afghanistan?

In 1939, Germany plunges Europe into war by breaking their promises for peace and marching into Poland. By the end of 1940 though, Britain is the only Great Power still standing against a seemingly invincible German juggernaut. On the surface, the war’s opening phase seems like Hitler’s crowning achievement, but did the first 16 months of WW2 actually lay the groundwork for his ultimate defeat?

The US invasion of Iraq was the culmination of several developments that started at the end of the Gulf War in 1991. In 2002, the Bush administration used the excuse of Weapons of Mass Destruction (WMDs) and claimed links between Saddam Hussein and al Qaeda to justify the invasion.

The Marine and US Army landing on the Tarawa Atoll's Betio and Makin islands were the first operations in the new Central Pacific front of the Pacific War. Tarawa was one of the deadliest amphibious landings for the Marine Corps which hadn't yet perfected such complex operations. But the lessons learned at Tarawa would already be applied a few months later at Kwajalein and Eniwetok.