When Nick Clegg warned of "Greek-style unrest"  if a government with only a slim mandate brought in fierce spending cuts, he was widely derided. Not in conservative Britain, they said. But after last night's events, his words now look like an understatement.
In truth, however, it is spurious to draw any connection between the cuts (most of which have not been made) and the nihilistic destruction (as Ken Livingstone rather unwisely did  last night) witnessed in London and other cities. In Croydon, a 144-year-old furniture shop was destroyed by fire, with nearby homes also engulfed. Marc Reeves, the owner of the store, later tweeted : "That shop in Croydon is on a street that bears its name: Reeves Corner. Established by my gt gt grandfather in 1867. Now gone." In Enfield, a Sony distribution centre was set on fire , triggering a huge blaze that, six hours on, is still raging.
But amid the destruction there were some heartening scenes. In Hackney, the location of much of the worst rioting, Kurds (some of them former Peshmerga  fighters) and Turks bravely defended their shops and restaurants with bats and sticks. A true English Defence League, as one friend put it to me. In a clip that has already gone viral, a West Indian matriarch  from the same borough confronted the rioters and ordered them to stop.
By the early evening, however, the rioting had spread to Birmingham, with widespread looting around the Bull Ring shopping centre, and an empty police station set on fire. In Liverpool, cars were set alight as police officers were pelted with weapons, with similar acts later witnessed in Bristol and Nottingham.
As he will know, David Cameron now faces the biggest test of his leadership to date. Like Boris Johnson and Theresa May, he wisely cut short his holiday and returned to London this morning. For Labour, Ed Miliband and Harriet Harman did the same as several MPs called for Parliament to be recalled.  In the short-term, we can expect the debate to focus on the police, who, by their own admission were overwhelmed last night. As the destruction mounted, there were calls, including from liberals, for the police to use water cannon (which would have to be imported from Northern Ireland) and rubber bullets, even for the army to be called in. But speaking this morning, May has already ruled out the use of cannon: "The way we police in Britain is not with water cannon. The way we police in Britain is on the streets and with the communities."
For now, an odd sort of calm reigns as the great clean up begins. But whether or not the rioting continues tonight, the country demands leadership. Will our politicians provide it?