Rezgui did not fit the profile of a fanatic. An electrical engineering student at the University of Kairouan, he came from Gaafour in northwestern Tunisia. Neighbors knew him as a skilled breakdancer. He had a girlfriend. He drank alcohol. He followed Real Madrid. The Islamic State claimed him as a soldier, assigning him the nom de guerre Abu Yahya al-Qayrawani, but the path from breakdancing student to mass murderer traced through the chaos that followed the Arab Spring and the collapse of neighboring Libya. His radicalization appeared to accelerate during the fall of Muammar Gaddafi's regime and the rise of the Syrian civil war -- the same geopolitical upheavals that were destabilizing an entire generation across North Africa and the Middle East.

The Sousse attack came barely three months after gunmen killed 22 people, mostly European tourists, at the Bardo National Museum in Tunis on 18 March 2015. Both attacks were claimed by the Islamic State. Together, they struck at the foundation of Tunisia's post-revolutionary economy: tourism. The attacks also fell on the same day as three other Islamist attacks worldwide -- a beheading at a French factory, a mosque bombing in Kuwait City that killed 27, and an assault on an African Union base in Somalia that killed 70. An IS leader had called for attacks during Ramadan days earlier, though no direct coordination between the incidents has been established.

The 38 people who died on the beach were not abstractions. They were retirees on package holidays, couples celebrating anniversaries, families with children. Among them was Denis Thwaites, a former Birmingham City footballer, and his wife Elaine. Three Irish citizens died, including a nurse well known in her community in Athlone. A German citizen, a Portuguese national, a Belgian, and a Russian were also killed. The British Foreign and Commonwealth Office changed Tunisia's travel advisory to 'advise against all but essential travel,' triggering the evacuation of an estimated 3,000 British nationals. Tour operators First Choice, TUI, and Thomson suspended all trips to Tunisia through at least October 2015. The country's tourism industry, which employed hundreds of thousands, faced collapse.

Tunisia's government responded with sweeping measures. Eighty mosques accused of inciting extremism were closed. New counter-terrorism legislation debated in parliament proposed expanded surveillance powers and the death penalty for terrorism-related offenses. The governor of Sousse and several local police officials were dismissed. On 4 March 2019, Prince Harry unveiled a memorial called Infinite Wave in Cannon Hill Park, Birmingham, honoring the British victims and a victim of the Bardo museum attack. The sculpture's curved steel bands evoke both ocean waves and the continuity of memory. Tunisia's young democracy -- the only Arab Spring country to emerge with a functioning democratic system -- faced the impossible task of protecting an open, tourist-dependent economy from the kind of violence that no security apparatus can fully prevent. The beach at Port El Kantaoui remains open. The hotels are still there. What changed was the understanding that even paradise has no immunity.