Franz Ferdinand was fully aware of the date's significance when he chose it for a tour calculated to flaunt the supremacy of the Austro-Hungarian empire (which had been more-or-less gifted Bosnia & Hercegovina by the Ottomans). Bosnia's Serbs would have been happy to have had a go at any Austro-Hungarian royalty foolhardy enough to show their faces in Sarajevo that day. It later emerged that there had been several would-be assassins along the route.

The Dual Monarchy, itching to get Serbia under its thumb too, seized on the assassinations as a chance to declare war (notwithstanding that the atrocity took place in Bosnia). They were taken aback by the strength of the Serb resistance, which would have succeeded but for a catastrophic outbreak of typhoid in their trenches.

Then, as in WW2, the Serbs were allied with Russia and the UK. It is a curious paradox that by the 1990s these allies of two earlier conflicts had become public enemy number one - even worse than muslims, whom the US raced to side with against them. The answer lies in US-admin paranoia about socialism, and the malign influence of the Vatican.