Last year, the spokesman of the Islamic State extremist group urged followers to "kill a disbelieving American or European -- especially the spiteful and filthy French" by any means that came to hand.
"Smash his head with a rock, or slaughter him with a knife, or run him over with your car, or throw him down from a high place, or choke him, or poison him," said Abu Mohammed al-Adnani, the group's spokesman.
The suspect, 35-year-old father-of-three Yassin Salhi, allegedly severed his boss's head and attached it to a fence before driving headlong into a gas factory in an apparent bid to blow it and himself sky high.
Nearby Salhi's almost destroyed vehicle, authorities found a knife, suggesting the suspect may have taken to heart Adnani's message to use whatever is available to sow terror.
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"We've gone from the hyper-terrorism of September 11 to a form of micro-terrorism," Alain Bauer, criminologist and author of a book on terrorism, told AFP.
"But the effect is the same whether there is one victim or 3,000," concluded the expert.