Here's What You Need To Remember: If twentieth-century Germany had a tombstone, it would say "This Is What Happens to Those Who Fight on Two Fronts".

When it comes to alternative history, the Second World War is king. Dozens of books and wargames suggest how history would have changed if Hitler had invaded Britain or not invaded Russia. Want to know what happens when a Nimitz-class supercarrier goes back in time to battle the Japanese fleet at Pearl Harbor? There's a movie for that. What would the world be like if Nazi Germany had won? Plenty of novels paint a dark portrait. Would the Third Reich have triumphed if it had developed jet fighters sooner? Such topics are like incendiary bombs on Internet chat forums.

Yet fascinating as these questions are, why are they any more fascinating than asking what would have happened if Imperial Germany had not invaded Belgium in 1914, if the Kaiser had built more U-boats, or if America had not entered the war? If it is plausible to imagine a historical timeline where Hitler won, then why not one in which the tsars still rule Russia, the British Empire was never exhausted by war, and the Ottoman Empire still controls the Middle East?

Perhaps it is the grim aura of fatalism that discourages speculative history of the Great War. The sense that no matter what, the conflict would have been one long, miserable slaughter, a four-year live performance of "Paths of Glory." But the combatants were not drones or sheep, and the conflict was more than mud, blood and barbed wire. There was mobile warfare in Russia and Poland, amphibious invasions in Turkey and guerrilla campaigns in East Africa.

It is also easy to assume that German defeat was inevitable at the hands of an Allied coalition richer in manpower, weapons and money. Yet Germany nearly captured Paris in 1914, crushed Serbia and Romania, bled the French Army until it mutinied, drove Russia out of the war, and then came oh-so-close to victory on the Western Front in 1918. Don't underestimate the power of Imperial Germany. Until the armistice was signed in a French railway carriage on November 11, 1918, Germany's enemies didn't.

So with this year marking the 100th anniversary of the War to End All Wars (but didn't), let's look at what might have been. Here are a few possibilities in which history could have been very different for Germany:

Avoiding a two-front war

If twentieth-century Germany had a tombstone, it would say "This is What Happens to Those Who Fight on Two Fronts". Much as kung-fu movies make fighting multiple opponents look easy, it's generally better to defeat your enemies one at a time.

That was the idea behind Germany's Schlieffen plan, which called for concentrating on France in the opening days of the conflict while keeping weaker forces in the East. The key was to defeat France quickly while vast and underdeveloped Russia still mobilized, and then transfer forces by rail to settle accounts with the Tsar.

However, Russia did attack into East Prussia in August 1914, only to be surrounded and annihilated at the Battle of Tannenberg. They lost 170,000 men to just 12,000 Germans in one of history's most famous battles of encirclement. Yet the Russian advance also frightened German Army Chief of Staff Helmuth von Moltke into transferring three corps from France to East Prussia. They arrived too late for Tannenberg, while depriving the Western offensive of vital troops at Germany's best time to overcome France and possibly end the war.

From then on, Germany had to spread its forces between West and East, while supporting its Austro-Hungarian and Turkish allies. Just what Germany could have accomplished—had it been able to concentrate on just one front—became painfully clear in 1918. After forcing the new Soviet government to sue for peace, the Germans quickly transferred 500,000 troops to France. They also unleashed innovative new stosstruppen (stormtrooper) infiltration tactics—an early form of blitzkrieg without the tanks—that enabled them to break the trench-warfare deadlock.

Kaiserschlacht ("Kaiser's Battle") offensives shattered several British armies and compelled British commander Douglas Haig to warn his troops that their backs were "to the wall." After four years of unrelenting combat and economic blockade, Germany still had the strength to achieve more in weeks than four years of bloody Allied offensives at the Somme, Passchendaele and Chemin des Dames.

Ideally, Germany could have found diplomatic means to have fought against Russia alone without war with France, or vice-versa. Failing that, and given the shorter distances in the West, it would have been better to have temporarily conceded some East Prussian territory while concentrating on capturing Paris. It might not have been easy, but it would have been far easier than fighting on two fronts.

Not Invading Belgium

Imperial Germany was a nation too clever for its own good. Case in point: invading neutral Belgium. From a military perspective, advancing to Belgium was a brilliant move to sidestep north of the French armies and fortifications on the Franco-German border, and then turn south to capture Paris and encircle the French armies from the rear. It reflected the traditional German preference for mobile warfare (Bewegungskrieg), which favored superior German tactics, rather than a static war of attrition (Stellungskrieg) that could only favor their numerically superior opponents.

A strategic masterstroke? Indeed. It also may have lost Germany the war.

Britain had guaranteed Belgium's neutrality. That "scrap of paper" had been derided by German leaders, but the parchment would cost Berlin dearly by giving London a casus belli to declare war. Now Germany faced not just France and Russia, but also the immense military and economic resources of the British Empire.

France had a population of 39 million in 1914, versus Germany's 67 million. Can anyone imagine France alone defeating Germany? It failed in 1870, and it would have failed in 1914. Russia could boast of a population of 167 million people, yet shortages of weapons, supplies and infrastructure rendered it a giant with feet of clay. Despite keeping much of their army in France, the Germans were still able to drive Russia out of the war by 1918. Without British support, even a Franco-Russian combination would probably have succumbed to German might.

The entry of Britain and her empire added nearly 9 million troops to the Allies. More importantly, it added the Royal Navy. The French battle fleet was half the size of Germany's and was deployed in the Mediterranean against Germany's Austro-Hungarian and Turkish partners. The Russian navy was negligible. It was Britain's Grand Fleet that made possible the blockade that starved Germany of raw materials and especially food, which starved 400,000 Germans to death and sapped civilian and military morale by late 1918.

It is quite possible that Britain might have declared war on Germany anyway, just to prevent a single power from dominating the Continent, and to preclude hostile naval bases so close to England. But if Germany had managed to stave off British entry for months or years, it would have enjoyed more time and more resources to defeat its enemies.

Don't Build a Big Surface Fleet

Imperial Germany's High Seas Fleet was the second most powerful navy in the world in 1914, behind Britain's Grand Fleet. It mustered fifteen dreadnoughts to Britain's twenty-two, and five battlecruisers to Britain's nine. German surface ships enjoyed better armor plating, guns, propellant and fire control systems than their British rivals.

And what did this powerful surface fleet accomplish? Not much. Its capital ships rarely left port, which also left the British blockade in place. If the German fleet could not break the British blockade, impose its own blockade of Britain, or enable a German amphibious invasion of England, then what was it good for?

It did have value as a classic "fleet in being", staying in port while waiting for an opportunity to pounce, and threatening the enemy just by its existence (Churchill described Royal Navy commander John Jellicoe as the only man on either side who could lose the war in an afternoon). But its main contribution was provoking the British into regarding Germany as a threat even before the war began. Challenging the Royal Navy's maritime supremacy through a naval arms race was the one move guaranteed to arouse the British lion.

Despite ambitions of becoming a global colonial empire, Germany was still a Continental power in 1914. If it won the war, it would be through the immense power of its army, not its navy. What could Germany have bought with the money, material and manpower tied up in the High Seas Fleet? More divisions? More guns and aircraft? Or best of all, more U-boats, the one element of German naval strength that did inflict immense damage on the Allies.

Don't Resort to Unrestricted Submarine Warfare

It appears such a quaint custom now. But in 1914, submarines were supposed to surface when attacking merchant ships, and allow the crew and passengers to escape. As nobly humanitarian as it was, it also left submarines more vulnerable.