On the other hand, it can be argued that Serbia started the war through an act of state-sponsored terrorism.
Most historians agree that the ultimatum served on the Serbians by the Austrians was indeed peremptory and frankly calculated to be unacceptable to the Serbians precipitating a war which the Austrians had long believed was unavoidable. Many historians also believe that the Serbs were complicit in the plot to murder the punitive successor to the Austro-Hungarian Imperial throne.
Imagine the consequences if there were irrefutable proof that the Cubans conspired to murder John F. Kennedy. War would have been inevitable.
I think there is a more important lesson to take from this tragic affair which destroyed the empires of four Imperial Royal families, Habsburg, Romanov, Hohenzollern, and Ottoman. The murder was surely one of the great dramatic turning point in history, marking the end of the old order which had been put together at the Congress of Vienna after the fall of Napoleon Bonaparte, and the beginning of the new age of industrial warfare. The world has never been the same since the assassination of Archduke Ferdinand but he was assassinated for ethnic grievances, whether real or imagined.
One ought to consider the consequences to the world of the enforced admixing of the Austro-Hungarian Empire the next time some left-wing American politician proclaims, "diversity is our strength."
Typically, left-wing politicians, whose wet dream it is to engineer society as though it were contained in a Skinner box, believe against all historical evidence that their superior ideology will achieve the seamless integration of all disparate ethnic, religious and racial tribes. This cosmic arrogance is today causing the ruin and of what is left of the realm of the last surviving Imperial house of 1914, the house of Windsor.
If history can teach us anything, it should give us pause to fear that we cannot be far behind Windsor.