The causes of WWI
On June 28, 1914, Gavrilo Princip (a Bosnian) shot and killed Archduke Franz Ferdinand, the heir to the throne of Austria-Hungary. He claimed at his trial that Ferdinand was "an enemy of the South Slavs". Actually, Ferdinand was the most powerful friend of the Slavs within the Austrian government, which should lead one to wonder who put Princip up to the deed (see below).
On July 5, (German) Kaiser William formally but secretly encouraged Austria to invade Serbia in response, and Germany kept sending aggressive messages to Austria, while Austria promised Germany to make demands on Serbia that "the possibility of its acceptance is practically excluded". Eventually, on July 23, under German pressure, Austria sent the note to Serbia, demanding an answer within 24 hours.
On July 24, Serbia answered, agreeing to nine of the ten demands. On July 28, Austria declared war on Serbia, and on July 29, Austrian artillery started a bombardment of Belgrade.
Russia had been friendly to Serbia (partly because both countries considered themselves "Slavic", partly because both countries were "Orthodox Christian", and partly because Serbia's geographic position made it more difficult for Austria to seize Ottoman territory near the Bosphorus, which Russia hoped someday to seize itself - Russia and Austria had been rivals since 1815 in the race to grab pieces of the Ottoman Empire as it fell apart) and had tried to dissuade Austria from attacking. After the bombardment began, Russia began to mobilize its army. On July 31 Germany demanded that Russia demobilize within twelve hours, and on August 1, Germany declared war on Russia.
Between 1815 and 1870, Russia and Prussia had been friendly partly because they cooperated in resisting Polish nationalist sentiment. Both empires contained a large Polish population. Any conflict between them could only be expressed by one grabbing more Polish territory from the other, and in Bismark's famous comment "We have too many Poles already". But the main reason the relationship was stable was that Prussia accepted its status as the junior partner - Russia was overwhelmingly bigger.
In 1870 France, alarmed at the growing power of Prussia, declared war but was soundly beaten. This raised the prestige of Prussia so high that the other German states had little choice but to accept the authority of the Prussian king, who thereby became the first German Emperor. Germany seized Alsace and Lorraine (which had large French and German populations). France had always considered itself the natural leader of Europe, and deeply resented the fact that Germany was now far more powerful than France, quite apart from the loss of territory. From 1870 to 1940, France was the most persistent opponent of Germany.
Between 1887 and 1894, Germany became unwilling to accept its position of junior partner to Russia, while Russia was unwilling to recognize that Germany's increasing wealth and power had changed the nature of the relationship. Germany refused to accommodate Russia as before, Russia was offended, and France jumped at the opportunity of replacing Germany as Russia's partner. Franco-German rivalry over Alsace-Lorraine and Russo-Austrian rivalry in Ottoman Europe were now linked together. Germany began to consider how it could fight France and Russia together. (Austria was much less powerful, but would help against Russia.) Since Russia was huge but poorly governed, it seemed that the best chance would be to crush France before the Russians could get themselves organized. The French realized this, and built a series of fortifications along their border with Germany, confident that this would hold the German army long enough for the Russians to organize and invade Germany. Between 1891 and 1906, Count Alfred von Schlieffen drew up an elaborate plan to avoid these fortifications (and the difficult country along the Franco-German border) by invading France through Belgium.
The fact that the war would start in the East therefore posed a terrible problem for Germany. If Germany sent her troops deep into Russia, there would be no way to resist a 'stab in the back' from France. So when Germany sent the demand to demobilize to Russia on July 31, it also sent to France a demand to hand over the border fortifications as a guarantee against such a stab. France refused, so Germany declared war on France on August 3, and asked Belgium to allow German troops through. Belgium refused. Germany invaded Belgium on August 4.
In 1839, Belgian neutrality had been guaranteed by Austria, Britain, France, and Prussia. This treaty was an expression of British policy that neither of the two best ports on the continental side of the North Sea (Antwerp and Amsterdam) be controlled by a large country, because they were the only plausible places from which an invasion of Britain could start. (In WWII the limited range of aircraft made the Dover-Calais route seem most plausible.) Would Britain fight for Belgium? This was a critical question, because Germany was (correctly) confident of beating France and Russia so long as Britain stayed neutral.
Until 1890, Britain would certainly have either stayed neutral or fought against France and Russia, her traditional rivals in colonial affairs. In 1890, Alfred Tirpitz became chief of staff to the German Navy High Command with the personal command of the Kaiser (the eldest grandchild of England's Queen Victoria) to build a navy second to none. "When, as a little boy, I was allowed to visit Portsmouth and Plymouth hand in hand with kind aunts and friendly admirals, I admired the proud English ships in these superb harbors. Then there awoke in me the desire to build ships of my own like these someday, and when I was grown up to have as fine a navy as the English." Tirpitz designed a fleet for the specific purpose of fighting the British in the North Sea. Until 1902, Britain and Germany continued to try to negotiate an alliance (potentially against France and Russia) but these negotiations failed essentially because each side saw themselves as the senior member of the alliance. Britain therefore looked elsewhere for useful junior partners, finding the first in Japan.
The man who did most to win WWI, Theophile Delcasse, foreign minister of France, studied the 1902 Anglo-Japanese treaty carefully. Four years before, Britain and France had nearly gone to war over a mud fort at Fashoda in the Sudan. Delcasse had lost considerable popularity in France (in his first weeks in office!) by insisting that France abandon Fashoda on the grounds that the principal threat to France came from German troops in the Vosges, not British troops in Africa. Then France had been enraged by the British annexation of the Boer Republic, 1899-1903. Delcasse remained resolute in his determination to establish the best relationship possible with Britain. "Ah, my dear friends, what beautiful horizons would open before us. Just think! If we could lean on both Russia and England, how strong we would be in relation to Germany."
There were many obstacles to Delcasse's vision. All over the world, French and British colonial interests collided. The British occupied Egypt, where the French considered they had rights. (The Fashoda crisis was essentially a French attempt to assert these rights.) Morocco was the subject of an 1880 neutrality treaty like Belgium's, but the government there was collapsing, and the French wanted to add Morocco to their empire in North-West Africa. Other collisions were smaller, but numerous. Delcasse's solution was simple and stunning - he would abandon French claims in and around Egypt in exchange for a free hand in Morocco, and he would settle all other colonial disputes with Britain on the best terms he could get, but settle them he would. But until the Boer war ended in 1903, it would be impossible for French public opinion to accept such a treaty. As soon as the war ended, Delcasse began negotiating (often without the knowledge or support of his government), and on April 7, 1904 the treaty was signed. At first, Germany saw no reason to object to the treaty, which concerned matters far from Germany, but gradually became aware that they could no longer rely on Britain and France remaining rivals. Then they objected, but too late.
On May 18, 1904 Moroccan rebels kidnapped an American and an Englishman, demanding (and getting) various concessions from the Sultan in exchange for their release. The French used this as a pretext for taking over Morocco, keeping the Sultan as a puppet ruler. Germany objected, hinting at an invasion of France unless the 1880 treaty was honored. Partly because of British concerns that the German navy was growing so fast, Britain backed the French position even more strongly than the French government (who fired Delcasse to appease the Germans) did. A conference took place to discuss the issue at Algeciras, near Gibraltar. The British Mediterranean and Atlantic fleets both anchored where they were visible to the negotiators, who agreed that France would have "special responsibilities" in Morocco, but would not formally announce a protectorate. Germany had demonstrated to the world that it was the main threat to peace, and Britain and France had learned to trust each other after centuries of rivalry.
In 1904, Britain's Far-East ally, Japan, shocked the world by defeating Russia. Russia was so humiliated that mutiny and revolution broke out but were eventually suppressed. Between the defeat and the chaos, Russian power was drastically reduced, but the government was shocked into various reforms which led to much greater economic and military growth in Russia. Germany realized that if it was ever to fight Russia, the sooner the better. To counter this threat, Russia followed the French example of removing all sources of colonial friction with Britain, in the treaty of August 31, 1907. This was also helped by British revulsion against the recent ethnic cleansing of Armenians by the Ottoman Empire, which Britain had previously defended against Russian encroachment.
If there can be said to be one man who defeated the Kaiser, it would have to be Theophile Delcasse.
In 1909, it became apparent in Britain that Germany was secretly building warships faster than the published schedule. Britain doubled its own rate of warship construction explicitly in response. Now Germany was openly the primary potential enemy of the next three strongest powers in the world.
Meanwhile France continued to consolidate her position in Morocco, despite continued German complaints. Eventually, Germany hatched a plan to make its displeasure felt. On July 1, 1911 the tiny German warship Panther dropped anchor in Agadir bay in South Morocco, allegedly to protect Germans in the area from rebellious Moroccans. Since there were no Germans in the area, the German government had instructed one Herr Wilburg to go there to become "the endangered German". Although he made heroic efforts, the journey was so long and difficult that he did not reach Agadir until July 4, and even then it took another day for Herr Willburg and the Panther to find each other. Again Britain strongly backed France, so Germany had to back down again, accepting a slice of relatively worthless land in central Africa as a consolation prize.
When Germany invaded Belgium three years later, Britain had to decide whether to allow Germany to occupy Antwerp in the hope of persuading a withdrawal after the war, or whether to intervene now, while Germany was fighting France and Russia. The German navy was already a threat to Britain, and would become much more threatening if it could cover an invasion from Antwerp. The aggressive German foreign policy since 1890 gave no assurance that Germany could be peacefully persuaded to evacuate Antwerp. If Britain was to fight, the sooner it began the better, because once France fell, prospects seemed dim. On August 4 1914, German troops invaded Belgium at 5am, and Britain sent a note to Germany at 2pm the same day stating that Britain would join the war at midnight unless German troops had left Belgium.
Germany soon learned that having the second-best navy is just as expensive and useless as having the second-best hand in a game of poker. German and Austrian commerce vanished from the seas, while British and French commerce continued as before. Germany could not feed itself, and Germans began to go hungry. Germany found itself with another difficult decision. Submarines had shown themselves to be unexpectedly potent weapons, and if used against commerce might make the British more hungry than the Germans. As the land war settled into stalemate, this seemed the only way to prevent Germany being starved into surrender. Unfortunately, Germany was signatory to treaties that prescribed strict procedures for warfare against merchant ships, and these procedures were essentially impossible for submarines to follow. Various neutrals, especially America, had issued strong statements that breaching these treaties would have dire consequences.
Already Germany had invaded France as the best way to defeat Russia, and invaded Belgium (thus pulling Britain into the war) as the best way to defeat France quickly. Now should they risk pulling America into the war in order to try to defeat Britain quickly? They changed policy on this several times, but eventually they did, and were defeated.
I have never seen any comment on what is apparently a very odd coincidence. The building of HMS Dreadnought in 1905 had caused great consternation in Germany as it became clear that it was impossible to build a ship that would match her and still be able to go through the Keil Canal. Germany decided to enlarge the canal to accommodate bigger ships. Germany's aggressive attitude led many (notably Admiral Fisher) to predict that Germany would start a European war as soon as the canal was finished. The widened canal was officially opened on July 1, 1914, only three days after Ferdinand was assassinated, but the Kaiser had personally inspected the canal (passing through in his official yacht Hohenzollern) on June 24.
Was the German intelligence service behind Princip's act? Germany's only real ally in Europe was Austria-Hungary, and Ferdinand's policies were likely to weaken Austria's dependence on Germany. Certainly Germany had much more to gain by Ferdinand's death than Serbia did. Not only did it preserve Austria as a reliable ally, but it brought about the war that the Germans certainly believed must be fought soon or never. (Russia had gone through internal convulsions in 1905, but was in 1914 rapidly modernizing and growing stronger.) Germany correctly believed that it could defeat Russia and France, but did not want to fight Britain. Britain had recently, against her own self-interest, stopped defending the Ottoman Empire against Russia because of Ottoman atrocities against Armenians. Did the Germans believe that Britain would also refuse to defend the supposed murderers of an Austrian Archduke?
It is said to be a common tactic of intelligence services to recruit fanatics by pretending to be from the party they support. No doubt CIA operatives are currently pretending to be Iranians as they try to recruit Iraqi Shiites. It is quite possible that Princip believed that he was working with Serb nationalists, when his orders were actually coming from Berlin.
Imperial Germany was just as ready as Nazi Germany was later to invent excuses for military action. Before invading France and Belgium, the German government produced a flurry of accusations that eighty French officers in Prussian uniforms had tried to cross the frontier in twelve cars; French aviators had thrown bombs onto rail lines in Nuremberg and Karlsruhe; a French physician had infected wells in Metz with cholera; the French army had crossed into Belgium for a sneak attack on Germany; etc. etc. It is hard to imagine they would have had moral qualms about organizing the shooting of a dangerous Austrian liberal for the same purpose.
Such a conspiracy would normally come to light after the war, or as the conspirators retired to write their memoirs. WWI was so disastrous for Germany that it seems reasonable to suppose that no-one would want their name associated with a plot to start it, just as no Americans that I know of have published memoirs claiming credit for the Bay of Pigs invasion.
Perhaps the best illustration of the fact that Germany, not Austria, was the driving force on the road to war is that Germany had already invaded Belgium before Austria declared war on Russia (after several indignant telegrams from Berlin to Vienna) and Austrian troops did not advance into Serbia (or Russia) until after the critical initial battles in France were over with 'the miracle on the Marne'.
So what drove Germany into its belligerent policies and then into war? As Prussia became Germany and continued to become more powerful, other countries were slow to accommodate themselves to the changing balance of power. Germans took this as a lack of respect for their new status. Kaiser William himself expressed this frustration in his person: his parents were both liberal Europeans and he felt obliged to repudiate any idea that he had been infected with his parents' lack of militant nationalism; and his left arm had been paralyzed at birth, making it a great effort to appear manly and Emperor-like. It would be easy to assert that William's inept blusterings were themselves a major cause of the war, but they would not have had much effect had they not resonated with a German public longing for the kind of international respect accorded to Britain and France. To this day, if you see a French tourist in Germany, he visibly expects and receives extra deference, which he would neither expect or receive in Britain or America.