On Friday, London police defused explosives in two Mercedes cars that had been loaded with gas canisters and nails and left in central London, and analysts have fingered the Al-Qaeda group as a possible suspect.
Car bombings are a daily danger in Iraq, and many of them are allegedly built and triggered by Al-Qaeda in Iraq, the local franchise of Saudi-born extremist Osama bin Laden's jihadi network.
But car bombs weren't invented in Iraq.
In 1920, Italian anarchist Mario Buda exploded a horse-drawn wagon packed with dynamite near Wall Street, killing 40 people in New York's financial district eight decades before the September 11 attacks.
Since then, similar car and truck bombs have been used by militants, intelligence agencies and criminals in conflicts as far apart as Northern Ireland, Colombia and Sri Lanka.
Nevertheless, reports of this week's attempted attack in London have drawn parallels with the campaign in Iraq -- despite no evidence being made public to link the design of th