The German, Russian, and Austro-Hungarian Empires, together with the French Republic, all entered World War I with plans for great offensives, and the United Kingdom quickly agreed to take part in the French offensive. But it is Germany's dramatic offensive in the West that attracts the greatest attention. It is often said that this was conducted according to something called the Schlieffen Plan, or that it should have been according to the Schlieffen Plan but wasn't. Germany's failure to knock France out of the war in the late summer of 1914 is often said to mark the failure of the Schlieffen Plan.
The actual facts are somewhat different. This Web page very briefly sorts them out, in quite simplified form. It has few links to other Web pages because there are few with accurate information. If you want references to accurate sources, the place to look is in the notes and bibliography of The Plan That Broke the World.
The first question is, Who was Schlieffen? Alfred von Schlieffen was a Prussian hereditary count (Graff) who became the Chief (Generalstabschef) of the Prussian Great General Staff (Große Generalstab) in 1891, directly under Kaiser (and Prussian King) Wilhelm II. As such he was responsible for the war plans not just for the Prussian Army but the armies of the other subordinate kingdoms of Bavaria, Saxony, and Würtemberg, all of which would join under the command of the General Staff Chief (acting in the name of the Kaiser) as the German Army in time of war.
Most of the surviving records from Schlieffen's time were destroyed in World War II, but historian (and retired career U.S. Army officer) Terence Zuber has carefully sifted everything that remains to build an outline of the Great General Staff's planning during Schlieffen's time in office and beyond.
At the end of 1905, just short of his 73rd birthday, Schlieffen retired by order of the Kaiser, who seems to have felt he was getting too old for so demanding a job. Immediately after his retirement, early in 1906, Schlieffen wrote a lengthy "think piece" (Denkschrift) which sketched a plan for an attack on France, with no other nations participating in the conflict. Schlieffen backdated this to 31 December 1905, the date of his departure, giving it some official coloration.
This think piece came to be known as the "Great Memorandum," or as the "Schlieffen Plan." At some point, perhaps in 1906 or perhaps not until later (but certainly by 1911) it was turned over to the Great General Staff.
The man who relieved Schlieffen as Chief of the Great General Staff, by order of the Kaiser, was Helmuth von Moltke. He's often referred to as Moltke the Younger, to distinguish him from his very eminent uncle and namesake who had been the Chief in an earlier day. The younger Moltke was a personal favorite of the Kaiser but he was an experienced and well-qualified senior officer. No one, however, (including him) rated him as the equal of Schlieffen or his eponymous uncle in terms of military brilliance. He had very broad responsibilities and worked hard at them. It's not known how much time he devoted to the study of Schlieffen's think piece, but he did review it and made some (largely critical) notes in 1911.
It was Moltke's famous uncle who had said that no plan survives first contact with the enemy; his nephew and Schlieffen both knew this very well. Yet planning exercises were essential, if only to accustom commanders and senior staff officers to thinking and communicating about the problems war would present. When not actually drawing up the next year's specific war plans the officers of the Great General Staff were engaged in a continual round of exercises, staff rides, and war games.
The focus was never to conquer more territory for the German Empire. The Empire's leaders wanted it to grow in power and prestige, but displayed no interest in conquering more land in Europe, land that would be inhabited by non-Germans. They already had as many non-German "Germans" as they cared for.
Instead, the assumption was that if there was to be a war it would come because France wanted one (perhaps to recover the provinces of Alsace and Lorraine that had been lost to Germany in the 1870 Franco-Prussian War.) This would mean a French attack, so the Germans could stand on the defensive, with all its advantages, and wait to go on the offensive until they had first decisively defeated the French offensive. Similarly, in the East they could employ a defensive-offensive strategy against Russia.
So most of the exercises, staff rides, and war games conducted by Schlieffen and then by Moltke followed the defensive-offensive pattern, albeit with wide variations. Recognizing the uncertainties of war, however, they also sometimes played purely offensive scenarios, in which the German forces thrust directly into France or (less often) Russia. Sometimes these ended in German victory, sometimes not.
In August 1914 the plan the German armies followed in the West was predominantly offensive. The main German force marched into neutral Belgium and then swung down into Northern France. The French were allowed to launch their own offensive in the southeast, where the terrain was much better for defense than offense.
The Germans did not have an overall manpower superiority to the French (and their British allies). They counted on tactical superiority on the battlefield and in fact in most cases it was found that a German battalion could win a reasonably even fight against a French or British battalion.
Moltke's plan was to outflank, or envelop, the left end of the Anglo-French line. But without superior numbers this was very difficult to do, even given tactical superiority. Ultimately it didn't work and the two sides, exhausted, settled in along a line that would not move much until the final paroxysms of 1918, and the defeat and destruction of the German Empire in November.
(The reasons for the 1914 failure and things that might have made a difference are analyzed in depth in The Plan That Broke the World.)
Here's a map showing how far the Germans got—their advance up to 9 August and the Battle of the Marne. At that time the left of the French line extended all the way to Paris, so the German armies had not even come close to achieving envelopment.
In the wake of the failure of the offensive to defeat the British and French in the West senior German officers were anxious to avoid blame. Moltke had been ousted just as soon as it became clear that his offensive was not going to work as intended, making him the natural target of blame. The criticism and controversy was kept muted as long as the war continued, in the name of national unity, but the gloves came off following the final defeat at the end of 1918. By that time Moltke was dead of a stroke. Several other prominent figures also had died and like Moltke could no longer defend their reputations.
But what precisely were they guilty of? Few wanted to disown the offensive itself, only its results.
A story line quickly emerged. The plan of 1914 had not been Moltke's but Schlieffen's, and Moltke had botched it. Had he followed it faithfully victory would have been assured, but he had been too tentative and cautious. He should have denuded the left wing of troops and put all his strength and effort on the right. Let the French thrust as far into Germany as they might—it would all be retrieved when the right wing encircled and annihilated them. Similarly, let the Russians penetrate deeply into Germany, even to the gates of Berlin. They could be dealt with when France was defeated. Only Moltke had lacked the strength to drive it through. That was why the war was lost and the Empire destroyed. All for lack of a supreme commander worthy of Schlieffen's mantle.
In all this, the details of the Schlieffen Plan were left rather vague, and the plan itself remained under lock and key. But that did not prevent authors and map-makers from laying it all out in tones of grave authority. Here is one widely-seen example:
(The blue arrows supposedly represent the French plan, the dashed red arrows are supposed to show the Schlieffen Plan. Both are highly imaginative, to say the least.)
The actual Schlieffen memorandum remained sequestered until the end of World War II in 1945, when it was presumed to have been destroyed (along with many thousands of other documents) in a British bombing raid. In fact a copy had been among the records swept up by U.S. Army forces and sent to Washington, where it was eventually found by Gerhard Ritter, a very prominent German historian. Ritter published the plan with his commentary; the English translation appeared in 1958.
The publication of the memo opened the way for much more critical analysis of its relationship to the events of 1914. But operational military history was not in fashion and so it was an opening that was little exploited. In fact, Figure 2 was drawn (or at least re-drawn) after the memo was published, but it's very misleading as a representation of what Schlieffen said.
Figure 3 is a much less misleading map, one that represents with reasonable accuracy what seems to have been the main variant as discussed by Schlieffen in the memo. Here the red lines depict the overall flow of the advance; Schlieffen did not identify specific armies.
Schlieffen anticipated that the French, with their right wing anchored in the strong defensive positions between Belfort and Verdun, would rush forces to Paris, which was a great railway hub and surrounded by a ring of fortresses. Thus to envelop the French left, the German right would have to surround Paris and thrust on beyond it to the south and east.
This was going to require a great many troops, far more that Germany had available in 1906 or 1914. Some historians have claimed that the necessary forces could somehow have been raised and equipped at the last moment, but it's very hard to see how this could have been done. It's even harder to see how they could have gotten to the Paris region and been supplied once there.
Moreover, aside from moving troops to Paris (so that his extra forces could surround and bottle them up) Schlieffen implicitly assumes that the French would do nothing important to upset the German campaign in the two months or so it would take to reach the stage shown in Figure 3. Simply to assume such passivity in the face of great danger is scarcely realistic. (The experiences of 1914 were to confirm that when faced with danger of envelopment French commanders almost invariably broke contact and fell back promptly.)
Finally, Schlieffen deploys no troops against Russia. Russia had long been allied with France against Germany and it's not entirely clear why Schlieffen felt he could ignore her. One suggestion is that because Russia had recently lost a war with Japan he imagined that she was incapable of any action to support France, but that would not at all have been a realistic evaluation, even in 1906, let alone 1914.
In summary, Schlieffen's memo failed to address or resolve the problems of raising substantial additional troops, of getting them to where they were needed and keeping them supplied, or of preventing the French from slipping away to the south. Moreover it gave the French and Russians freedom to thrust deep into Germany with little opposition or even none whatever, and gives no indication of how they could be prevented from inflicting damage the Empire could not afford, militarily or politically. That is to say that the sketch Schlieffen offered in his memo fell far short of a complete or practical plan.
A major strain in German historiography, spearheaded in the 1960s by Fritz Fischer, also very prominent, holds that World War I was deliberately started by Germany in order to achieve "world power" (Weltmacht) and specifically to seize territory in Europe. His views found many supporters in Germany and elsewhere in Europe, although many believe that his evidence does not actually go far toward proving his case. (I am among these skeptics.)
In the eyes of many supporters of the Fischer view the Schlieffen Plan (which they usually conflate with the actual plan of August 1914) with its purely offensive focus is among the proofs of German aggression. Those who have studied military history tend to view this with skepticism, noting that it is widely believed that "the best defense is a good offense," implying that offensive strategies can be employed to defend as well as to conquer.
In any event, if we are to take purely offensive war plans as proof of aggressive intent then we must convict Austria-Hungary, Russia and France equally with Germany, and note that Britain was an accessory before the fact to French aggression. That is, all of these nations too had offensive plans; the distinction is only that they were less nearly successful than Germany in carrying them out.
As I've noted above, Schlieffen's sketch of a plan in his 1906 "think-piece" memorandum has many serious problems that would have made it impossible to implement as written, whether in 1906 or 1914. It is possible, as some believe, that the actual German plan of August 1914, whose results are outlined in Figure 1, arose by fleshing out and modifying the sketch plan of the 1906 memorandum—it's not something that can be proven or disproven on the basis of the available evidence.
It's not impossible that the Germans could have inflicted a much more serious defeat on the French in August 1914 with Moltke's plan, even conceivable that they could have knocked them out of the war and forced Paris to sue for peace. But it would have required substantially poorer performance by the French command, as well as better luck for the Germans. In fact, as The Plan That Broke the World shows, by 24 August Germany had lost her best opportunity to win of the entire war.
The book details how it could all have been different. In fact the German high command passed up options that could have given them both a much better chance of meeting the nation's political objectives and a softer landing if things went against them. Regardless of how one feels about the possibility of a German victory, ending the war reasonably quickly, on the basis of a negotiated settlement, would almost surely have resulted in a better world—to say nothing of sparing tens of millions of people from utter misery and terrible loss.
— William D. O'Neil