On July 28, 1914 the Archduke Franz Ferdinand, heir to the throne of the Empire of Austria-Hungary was assassinated, along with his wife Sophie, in the streets of Sarajevo, a town within the empire's province of Bosnia Herzegovina. It was only happenstance, a wrong turn by the driver of the Archduke's open top car shortly after several abortive attempts by pistol and bomb to kill him, that placed the occupants of the vehicle in the direct path of fire for a 19 year old Serbian nationalist, Gavrilo Princip. The wrong turn occurred in the wake of the Archduke's impromptu decision to go to the hospital to visit those wounded in the earlier bombing; as Ari Shapiro noted in a report on NPR:
"Today, if something like that happened, the vehicles would race away from the scene as fast as they could . . . But not in 1914: This was European nobility at the turn of the century."
The killings precipitated a chain of events, unforeseen by most in the immediate aftermath, leading to Austria-Hungary's declaration of war on Serbia on July 28 and a week later the entry of Russia, Germany, France and the United Kingdom into what was to become known as World War I ending the long 19th century that began in 1789 with the inauguration in April of George Washington as President of the new American republic and the start of the first phase of the French Revolution that summer.
(Man in funny hat & moustache shot; millions die)
(Princip)The path to war prompts one to think about the larger issues of how best to react to provocation and the unpredictability of events following both the provocation and the reaction which has continuing relevance for all of us. The plot to kill Ferdinand was directed and assisted at fairly high levels with the government of Serbia with the gang of assassins launched from that country into Austria-Hungary with the assistance of a covert organization associated with the Serbian intelligence services. Ideologically, Serbia was committed to the "liberation" of the South Slavs of Bosnia, Herzegovina, Croatia and Slovenia and their incorporation into a large Slavic state but the existing state was an unstable and violence wracked place.
Austria-Hungary was an increasingly ramshackle remnant of medieval Europe, Under Hapsburg rule for centuries the weakened dynasty was forced in the 1860s to creating an elevated role for the Magyar nobility of Hungary in a joint enterprise (thus the dual name and its becoming known as the Dual Monarchy though the monarch, Franz Josef, uncle of Franz Ferdinand, was the same for both parts) and resting upon a rising tide of unsettled and dissatisfied minorities - Croatians, Bosnians, Slovenians, Bohemians, Moravians, Slovakians, Ruthenians and other scattered ethnic minorities. The existence of Serbia (which had regained meaningful independence from the Ottomans only in 1878) was seen as an existential threat to the Empire by both Hungarians and the Germans of Austria because it served as a beacon of liberation for its fellow Slavs and was supported by Russia, the archenemy of the Empire. There were many, including the leaders of the Army, looking for an excuse to launch a war to eliminate Serbia fearing that if that did not happen the Empire would eventually collapse.
(The assassination site is at the beginning of the small street at the end of the bridge, just to the left of the building labeled Museum. The Archduke's car was headed on the road along the river from right to left and instead of continuing straight, mistakenly turned right. When the driver realized his error he stopped the car and prepared to back up. It was at that moment that Princip stepped up to the car and fired. Photo from NPR.) The Archduke Ferdinand was unpopular with the Hungarians, the army and his uncle because, among other perceived shortcomings, he was an advocate of raising the South Slavs to an equal partner with the Germans and Hungarians within the Empire, which he saw as essential to maintaining its stability, and opposed war with Serbia.
The assassination was immediately seen by many in the Empire as the chance to eliminate the Serbian menace. On July 5, 1914 the German government issued the famous "blank check" to its Austrian allies, pledging its support for whatever its actions against Serbia would be. The demands formulated by the Austrians were designed to be unacceptable to the Serb, though in the end they accepted almost all of them. The United Kingdom made several proposals for international mediation of the dispute but all were rejected by the Austrians.
Because the Serbs failed to accept all of Austria's demands war was declared on July 28. The result was cataclysmic. Serbia itself ceased to exist from 1915 to 1918, approximately 10 million were killed during the four years of war and by its end the monarch of Austria-Hungary, the Ottoman Sultans, and the Emperors of Russia and Germany had lost their thrones (and, in the first two instances, the empires themselves broken up) and the scourges of Communism, Fascism and Nazism had been, or were shortly to be, unleashed on the world.
Certainly in retrospect it would have been better for Austria-Hungary to accept the Serbs' agreement to most of its demands which would have effectively crippled the state at least in the short-term and would have bought some time for the Empire or to agree to the suggestions for international mediation which would probably have had the same effect. Instead the course chosen by its advocates resulted in the destruction of what they sought to preserve.
How far to go in responding to provocations, particularly provocations that are likely to continue is an unsettling topic and certainly THC has no idea what the right answer is except that he is confident that there is no one right answer to serve for all circumstances. Our past experiences tied with fears of the future often combine to mislead us but it remains difficult to distinguish between when we are being misled and when our experiences and fears are the basis for accurate forecasts.
In 1938 the scars of the World War and of those weeks between Ferdinand's death and the beginning of the war was one of the impetus for Neville Chamberlain's proposal to Adolf Hitler for what ultimately became the Munich Conference which led to the dismemberment of Czechoslovakia and proved to be a stepping stone to World War II. Though rightfully seen today as a disaster, it is also understandable how the horror of the First World War and of statesmanship in July 1914, prompted Chamberlain to try everything to attain peace. As Winston Churchill noted in his November 1940 eulogy for the former Prime Minister:
"It fell to Neville Chamberlain in one of the supreme crises of the world to be contradicted by events, to be disappointed in his hopes, and to be deceived and cheated by a wicked man. But what were these hopes in which he was disappointed? What were these wishes in which he was frustrated? What was that faith that was abused? They were surely among the most noble and benevolent instincts of the human heart--the love of peace, the toil for peace, the strife for peace, the pursuit of peace, even at great peril, and certainly to the utter disdain of popularity or clamour."Of course, in 1938 Churchill had said of the Munich agreement "Britain and France had to choose between war and dishonour. They chose dishonour. They will have war". Then again, Churchill was grievously wrong in his forecasts on many other issues, though if you are right on the biggest issue of your lifetime a lot can be forgiven.
We can also see this difficulty with the mix of past experience and future fears in America's experience with Iraq. After the First Gulf War in 1991, U.S. intelligence analysts were shocked to find that their pre-war assessments had massively underestimated the chemical and biological warfare capabilities of Saddam Hussein. Even in the aftermath of the war, our intelligence services failed to realize the Saddam had an ongoing advanced nuclear program which was not discovered until his two son-in-laws defected to Jordan in 1994. It's now clear that the U.S. intelligence community response to these underestimations led to a massive overestimation of Iraq's biological and chemical warfare capabilities in the years leading up to the 2003 invasion and that this past experience made it easier for policymakers and the public to accept those assessments.
The diplomatic mistakes of July 1914 seem obvious to us now but we know from our own experience that it often looks different when the events are happening around you compared to when you can reflect upon them after the events and their consequences have played out.
As is often appropriate, let's have Mr Churchill give the final benediction on this subject (also from his eulogy for Chamberlain; you can read the whole thing at A Lesson In Rhetoric):
"It is not given to human beings, happily for them, for otherwise life would be intolerable, to foresee or to predict to any large extent the unfolding course of events. In one phase men seem to have been right, in another they seem to have been wrong. Then again, a few years later, when the perspective of time has lengthened, all stands in a different setting. There is a new proportion. There is another scale of values. History with its flickering lamp stumbles along the trail of the past, trying to reconstruct its scenes, to revive its echoes, and kindle with pale gleams the passion of former days. What is the worth of all this? The only guide to a man is his conscience; the only shield to his memory is the rectitude and sincerity of his actions. It is very imprudent to walk through life without this shield, because we are so often mocked by the failure of our hopes and the upsetting of our calculations"
(Walters) 
(Anne Jackson)
(Collecting the dead at Cold Harbor, a year later)
(Pontoon bridge from Wikipedia) failed to realize that Grant's objective was Petersburg. By June 15, Union Army was approaching the outskirts of Petersburg. The defense of Petersburg was in the hands of General Pierre Gustave Toutant Beauregard, who had presided over the attack on Fort Sumter that started the war and then commanded the Confederate Army at the First Battle of Bull Run, both in 1861.
(Gen. Beauregard)
(Monument to 1st Maine at Petersburg)