The announcement of the government’s plans for a programme of events to commemorate the First World War is welcome, not least because policymakers should know and understand the nature and consequences of conflict. To learn any broader “les sons”, it is necessary to re-examine what led to the war. It is tempting to look for large causes, given that July 1914 started a chain reaction that led to two world wars and a European “civil war” that lasted until 1989/91. But, in doing so, historians often paint a picture of an inevitable conflict, of Europe reaching boiling point and then exploding violently. That would be the wrong lesson.

Crucial to understanding what happened in 1914 is that strange dialogue between the broader system of international politics, with its alliance structures, accepted norms of behaviour and crisis mechanisms, and the actions of individuals. The various diplomatic moves were made by individual decision-makers around the two kaisers in Vienna and Berlin and the tsar at St Petersburg, as well as ministers and officials in Paris and London. Their perceptions and miscalculations plunged Europe into the first general war since 1815 and ushered in the short 20th century. If anything, the haphazard and chaotic nature of decisionmaking belies assertions of Europe’s ineluctable progress to war.

The decision-makers of 1914 could not know their future any more than we can know ours. It is therefore important to appreciate the elements of risk and uncertainty their calculations contained. International crises generate their own dynamic and internal logic, of which events are both cause and consequence – and it is here that 1914 offers lessons.

There is a paradox about 1914: it should have been an unremarkable year. After years of turmoil, the short-term indicators pointed towards peace. European diplomats spoke of a new era of détente. But the two recent Balkan conflicts in 1912 and 1913 had left behind live ordnance, one being Albania, now independent but without agreed frontiers. For Austria-Hungary, the new state was vital to keeping Serbia landlocked. Conversely, for Serbia, it was a roadblock on the way to fulfilling her “Yugoslav” ambitions. Bulgaria, leader of the Balkan states in 1912 and then attacked by them in 1913, wanted revenge for defeat in 1913 and gravitated towards Vienna. Behind them hovered Russia, divided over whether or not to embrace a historic mission to lead the smaller Slav nations. At Belgrade, the government of Nikola Pašic, a wily survivor of the vicissitudes of Serb politics, was under threat from rogue elements in Serb military intelligence – elements that had equipped and trained a band of assassins now lying in wait at Sarajevo for the heir to the Habsburg throne, Archduke Franz Ferdinand, to pay his long-scheduled visit.

The fuse had been shortened in other ways, too. To Austria, Serbia’s growing power was a source of profound concern for the cohesion of her multi-ethnic empire. By now Habsburg policy, focused entirely on the Balkans, was suffering from tunnel vision. Broader European considerations scarcely mattered; these were left to the ally in Berlin. There, recent events had heightened expectations of a third round of war in the Balkans, but they had also sharpened fears for the survival of the Danube monarchy. This merely added to that strange amalgam of hubris and paranoia that characterised German foreign policy. Russia and France had also taken steps that made any future Balkan conflict riskier. Russian policy had gradually shifted from its initially pan-Slav orientation to one more narrowly pro-Serbian. At the same time, the French president, Raymond Poincaré, had unilaterally tightened France’s commitment to Russia: “If Russia wages war, France will also wage war,” as he said, no matter what the cause or the theatre of the conflict.

Against this background of competing currents Franz Ferdinand visited Sarajevo, capital of the Austrian-annexed province of Bosnia- Herzegovina. In many ways, the chaos and confusion of 28 June 1914 set the tone for the crisis that followed. The near bungling of the attempt on the archduke’s life was remarkable enough, the incompetence of the Austrian security forces still more so. The violent death of the archducal couple – assassinated by the Slav militant Gavrilo Princip – appalled Europe. It was generally accepted that Austria- Hungary was entitled to some form of retri - bution. Immediate military action might have made a continental war unlikely. Indeed, it is a further irony that the archduke’s murder had removed the one man who had restrained the “war party” at Vienna.

No attack on Serbia was possible without German support, and Berlin’s initial reaction was not encouraging. This changed when Kaiser Wilhelm intervened in German diplomacy on 4 July. Tone-deaf to nuances and colour-blind to shades of grey, he was given to exuberant outbursts: “The Serbs need to be sorted out, and soon.” The “blank cheque” of 5 July, a promise of unconditional support for Vienna, had profound implications. Some historians have argued that Germany had already decided on war 18 months earlier. This is problematic. The so-called war council of 8 December 1912 was preoccupied with the Balkan wars, and afterwards, significantly, Berlin made no military preparations. Indeed, on hearing of the council, the German chancellor, Theobald von Bethmann Hollweg, wearily dismissed it as the kaiser “playing at war again”. In July 1914, German support to Austria was given almost casually. There was no “calculated risk”, nor was any consideration given to the likely consequences of taking this step. Crucially, the blank cheque left Berlin unable to restrain Austria-Hungary.

In Britain, ministers were preoccupied with Irish matters, but London’s policy towards the events on the Continent was by no means passive. Contrary to his many detractors, Sir Edward Grey, the Liberal foreign secretary, intervened early, on 6 July. There were good reasons for him to stay in the background, however, not least the recent Anglo-German détente. The Germans had loyally seconded Grey’s efforts to mediate in the Balkan wars in 1912-13, while relations with France and Russia had cooled. The Foreign Office was doubtful whether the 1907 Anglo-Russian convention could be renewed in 1915. The agreement had helped to safeguard Britain’s imperial interests in central Asia, but had the pleasing effect of drawing Britain and Russia together in Europe. If it now collapsed, relations with Russia’s ally France, too, would become more distant. Grey and some of his advisers were looking for alternative options. For that purpose, a clandestine mission to Germany by his private secretary to explore the possibility of improving relations with Germany in private talks with the German foreign minister, Gottlieb von Jagow, was planned. These plans were overtaken by events in July.

The French public, meanwhile, was transfixed by the case of Mme Caillaux, the wife of the former finance minister, who had shot a newspaper editor who was critical of her husband. The French government, a coalition of disparate parties, was fragile and at odds with the right-wing president. Yet politicians of all stripes were anxious not to strain the Russian alliance, whose maintenance outweighed all other considerations. Russia moved with caution. There is no evidence of Russian involvement in, or foreknowledge of, the Sarajevo plot – regicide did not suggest itself as sound policy to the Russian autocrat. Nor was Austria-Hungary’s destruction on Russia’s agenda. If anything, Russian officials were anxious to believe Vienna’s assurances of pacificism.

In the meantime, reconciling the two halves of the dual monarchy made Habsburg decisionmaking excruciatingly slow. Without the agreement of the Budapest government there could be no war, and the Hungarians were wary of absorbing yet more Slavs into the empire. It was not until 19 July that Austro-Hungarian ministers, meeting secretly, decided on war.

There were yet further delays, caused by Austria’s decision to release most of the army on harvest leave. The pre-industrial Habsburg economy thus made a swift strike against Serbia all but impossible. A long-planned state visit to St Petersburg by Raymond Poincaré and his prime minister brought about another pause. From Vienna’s perspective, France and Russia could not be allowed to co-ordinate policy. Seen this way, tactical considerations demanded delay and trumped the earlier strategic decision for war, until the two Frenchmen left Russia on 23 July.

Even now, a military strike against Serbia could have been averted when Poincaré hinted that “Serbia had friends”. Vienna was set on war and no longer co-ordinated its policy with Berlin. Too great was the fear that the German leadership might retract the promise of unconditional support or that news of the impending strike against Serbia might leak out. German officials were happy to let matters drift.

Vienna’s ultimatum of 23 July 1914 was designed to be rejected. The Serb government accepted nine of its ten points and half conceded the other (the presence of Austrian police on Serb soil) – to no avail. Vienna wanted war. Grey’s warnings went unheeded, but he continued to offer his services as a mediator. His efforts were by no means half-hearted but a carefully calibrated crisis strategy, if one subject to the constraints imposed on the foreign secretary by Britain’s fragile domestic situation and the need to avoid binding foreign policy commitments. He proposed joint mediation by Britain, Germany, France and Italy if Russia intervened, so escalating the dispute, on condition that Vienna and St Petersburg halt any military preparations while the diplomats got to work. Given the information available, Grey’s proposals were sensible enough. There were problems, however. French support could no longer be had if mediation meant restraining Russia; now it could only work with German support. This became even more pressing once St Petersburg decided, on 24 July, on a “twintrack” strategy of diplomatic pressure amplified by partial mobilisation. Anxious to maintain her ally’s position, Germany was not likely to accept overt pressure on Austria-Hungary as part of any international crisis management. The diplomatic moves by Russia and France made Grey’s task even more complicated.

At St Petersburg, the French ambassador, Maurice Paléologue, played his own game. A hardliner, he withheld crucial information from Paris, such as Russia’s decision to commence partial mobilisation on 25 July; he also encouraged the Russians to harden their position. His assurances of absolute French support exceeded his instructions, but divisions among senior French politicians allowed him to pursue his own line of diplomacy. The incompetence of Russian officials complicated matters, for it was by no means clear what precisely “partial” mobilisation was meant to be.

War was still not imminent, however. Austria was not ready to strike, and mediation efforts continued. Grey renewed his proposal for a conference on 26 July, and the German chancellor sought to extricate Berlin from its commitment to Austria-Hungary. Indeed, as if to underline the lack of coherence in German policy, the kaiser now decided that Serbia’s response to the ultimatum had removed “every reason for war”. But that same day, German military intelligence picked up evidence of Russian troop movements. If correct, it threatened to unravel Germany’s sole war programme, the “Schlieffen Plan”. Localisation of the conflict in the Balkans no longer seemed possible, and growing awareness of this shook the confidence of Germany’s leaders.

The final attempts by Britain and Germany to localise the Austro-Serb conflict ran into another problem: the Habsburg commander’s campaign plan. Vital to their proposals was to allow Austria-Hungary to occupy the Serbian capital until Serbia fulfilled whatever obligations the powers decided to put on her. But Field Marshal Conrad von Hötzendorf was preparing to strike away from Belgrade; he wanted to destroy Serbia’s army, not occupy her capital. There was a further complication. By now, news of Russia’s mobilisation dominated the thinking of diplomats. In vain, the German chancellor sought to reverse policy during the night of 29-30 July, simultaneously trying to force Russia to disengage. Crucially, Germany’s ambassador, Heinrich von Tschir - schky, a hardliner who favoured war, did not transmit the chancellor’s warning that Germany refused to be “dragged by Vienna, recklessly and without consideration of our advice, into a global inferno”. At the same time, the German demand for the immediate cessation of Russia’s mobilisation merely confirmed suspicions in St Petersburg that Austria-Hungary and Germany had colluded from the start. The tsar’s foreign minister, the usually timid Sergei Dmitrievich Sazonov, refused to comply and the government ordered general mobilisation on 30 July.

This did not imply that war for Russia’s army, unlike Germany’s, could be stood down again. But German military planning, obsessed with the spectre of a two-front war, was predicated on speedy mobilisation, followed by the immediate commencement of operations before France and Russia had completed their deployments. Delaying mobilisation entailed losing the initiative; Germany might become bogged down in a protracted, defensive war. Not responding to Russia’s early mobilisation was a risk that the German military leadership decided it could not take.

In consequence, on 31 July, Berlin declared a “state of imminent danger of war”, one step short of general mobilisation.

Even now war was not inevitable, but Russia’s next move was critical. When on 1 August the Russian mobilisation order was not revoked, Berlin ordered full mobilisation and declared war on Russia. This triggered the Franco-Russian alliance, and France began to mobilise. Germany was now trapped by her own military planning. Having declared war on Russia because Russian mobilisation threatened to derail operations that had not even begun, Germany’s only war plan required a huge thrust against France first, and now French mobilisation threatened to derail that, too. Thus, in response to French mobilisation, Germany declared war on France on 3 August and during the night German forces began to pour into Belgium and Luxembourg.

All British efforts to mediate came to an end. The cabinet had never explicitly sanctioned an ultimatum to Germany and ministers had delayed their decision until the last possible moment. They were divided, and so was the country. Any precipitate decision for war threatened to split cabinet and country down the middle. The ultimatum had been implicit, however, in the cabinet’s authorisation of Grey’s speech to parliament on 3 August, in which he pledged to uphold the neutrality and independence of Belgium. Thus, at midnight, Berlin time, on 4 August 1914, a British ultimatum calling on Germany to halt operations in the west expired. Ninety-nine years of practically uninterrupted peace came to an end; the self-destruction of Europe had begun.

The events of July 1914 are no quaint period drama. It would be crass presentism to suggest that they offer neat “lessons of history”, yet the concerns of the years leading up to 1914 are more immediate to us today than the seemingly closer events of the 1970s. In the 21st century, as multiple power centres compete for economic, military and political influence, the contours of the 1914 international landscape look familiar again. Whether over Libya in 2010 or the euro now, leaders broadly agree on which outcomes are desirable and which are to be avoided, yet they have used undesirable outcomes to gain leverage and extract advantage for themselves. In 1914, none of the powers wanted a European war but they used the spectre of conflict for their own ends. They miscalculated. They lost sight of the bigger objective. And it is in this respect that 1914 is a warning from the past.

T G Otte is professor of diplomatic history at the University of East Anglia. He has been an adviser to the Foreign Office