The horror of the attacks in the city of Volgograd is shocking, even by Russia's grim standards. We have become accustomed to terrorists' indiscriminate choice of victims and locations. We have even become accustomed to the lethal choreography of simultaneous attacks.
But in Volgograd the bombers cold-bloodedly returned on Monday, 24 hours after Sunday's attack and two months after another attack in the same city, killing a further 14 people on top of the 23 earlier victims. They are not just organised and merciless, but horribly confident too.
The security services were on high alert. Ordinary citizens were looking for suspicious behaviour. The bomber got through anyway.
To find anything in Russia that is comparable, we have to go back to 1999, when a series of bombs – spaced out over a single September week -- demolished apartment buildings in Moscow and the town of Volgodonsk, killing hundreds. Officials appeared powerless and ordinary Russians panicked.
The prime minister, a little-known ex-KGB agent called Vladimir Putin, blamed the Chechens – despite their denial of responsibility – and sent in the troops. The army's crushing of the fragile self-declared Chechen state was the first battle in Putin's long campaign to reverse Russia's post-Soviet collapse, which had been symbolised by Boris Yeltsin's humiliating defeat by the separatists of Muslim Chechnya.
Putin, who was to become president within a year, took no chances. His artillery demolished Grozny to prevent rebels using it as a stronghold. His security services – as we know, thanks to the European Court of Human Rights – murdered rebels they captured without any pretence of a trial. Men were tortured. Women were raped. Artillery shelled the slopes of the Caucasus Mountains.
The relentless nature of the campaign gave Putin a blueprint for all his battles. When he decided to tame the oligarchs who had undermined Yeltsin, he jailed the richest of them – Mikhail Khodorkovsky – and took away his oil company. The others got the message.
This technique of No Surrender worked as well on uppity journalists, on performance artists who protested in a cathedral, on environmentalists, on the ex-Soviet state of Georgia, as it had on Chechens and oligarchs. Thanks to Putin, Russia went from being the sick man of Europe, to a tough-minded protagonist in what some called a New Cold War.
He was so sure of the progress Russia had made under his stewardship that in 2007 he bid for the Olympics, and won the right to hold the Winter Games in the Black Sea resort of Sochi in 2014. What better way to show that Russia was back than to host the world's biggest winter party?
But across the mountains from Sochi, all is not well. Putin might have killed the rebels' leaders, but the rebels remain. An independent state is out of reach, so these young Muslims have ceased fighting for one, or for anything concrete at all. They fight for vengeance, through rage, or to fulfil the tenets of a religion twisted and distorted in the fire of war.
Since Putin "pacified" Chechnya, suicide bombers have struck airports and planes, stations and trains, streets and buses, rock concerts and markets.
The attacks have achieved nothing but misery and death, but they have kept coming.
Putin has tightened regulations, and given more power to his security services. His agents have pursued young Muslims they suspect of being terrorists, but that has angered the young men further. Tens of thousands of Chechens have fled Russia, and taken violence with them. There are Chechens fighting in Syria. This year, two refugees bombed the Boston Marathon.
Fighting spilled over into nearby regions of Russia also, and the bombers now are mainly from neighbouring Dagestan, a bewildering multi-ethnic sinkhole which is never plugged, no matter how much money Moscow pumps into it.
Insurgents there long ago ceased having a cause beyond revenge. The web of feuds their fight with the police has created may never be unpicked.
Putin is so keen to see his Olympics go smoothly that last week he anticipated criticism and freed Khodorkovsky, the performance artists of Pussy Riot and a Greenpeace crew that had protested against oil drilling in the Arctic.
But he still faces his oldest foe – murderous fanatics with bombs – and they are determined to spoil his party.
He only knows one approach, and that is to get tough. In response to Volgograd, he has decreed three years in prison for anyone espousing separatism. Some of his allies have proposed restoring capital punishment, apparently without noticing that suicide bombers do not fear death.
Getting tough has not worked before, and there is no reason to suppose it will now. With the Olympics little over a month away, Putin has neither the time nor the inclination to change course. As long as both the Kremlin and its opponents pursue peace through war, we will see many more days like this one.
Oliver Bullough is the author of Let Our Fame Be Great, journeys among the defiant people of the Caucasus.