The next Russian Revolution started this month. It will be another two or three or even four decades before the Russian people take to the streets to overthrow their dictator — and the timing will depend more on the price of oil than on anything else — but as of Sept. 24, revolution rather than evolution became Russia’s most likely path in the medium term.

That’s because President Dmitri A. Medvedev’s announcement last weekend that he would step aside next March to allow Vladimir V. Putin to return to the Kremlin was also an announcement that the ruling clique failed to institutionalize its grip over the country.

We have known since 1996 that Russia wasn’t a democracy. We now know that Russia isn’t a dictatorship controlled by one party, one priesthood, or one dynasty. It is a regime ruled by one man.

“The party doesn’t exist,” said one of Russia’s leading independent economists. “The politics is all about one person.”

“There is no such thing as Putinism without Putin,” Nikolas Gvosdev, a professor of national-security studies at the US Naval War College, wrote this week in The National Interest. “Putin must still remain personally involved and at the helm for his system to function.”

That new reality might seem to be a victory for Putin. But it is a flawed triumph. His resumption of absolute power is also an admission that he and his cronies have failed in the project they set themselves in 2008. And that failure leaves the future President Putin with an Achilles’ heel.

The project was to create a self-replicating institutional base for the regime Putin brought to power in 2000, when he took over from Boris N. Yeltsin and dismantled the fledgling democratic structures the first leader of independent Russia had either created or tolerated.

“In 2008, Putin’s message was, ‘We aren’t like a Central Asian republic, we aren’t going to build a personalistic regime, we will have institutions,”’ Ivan Krastev, chairman of the Center for Liberal Strategies in Sofia and one of the most astute students of Russian power, told me. “This is all abolished now. The very idea of a governing party and party career, as you have in China, that didn’t work.”

Russia’s transformation into what political scientists call a sultanistic or neo-patrimonial regime is a break both with Russian history and with the global trend. The Kremlin has been home to plenty of murderous dictators. But the czars drew their legitimacy from their blood and their faith. The general secretaries owed their power to their party and their ideology. Putin’s rule is based solely on the man himself.

Russia’s shift to sultanism is out of step with the rest of the world, too. The Arab Spring was a revolt against some of the world’s most powerful neo-sultans; it is no accident that most of the remaining Middle Eastern dictatorships are ruled by dynastic monarchs, not strongmen. And among the world’s great powers — a group to which Russia is desperate to belong — only the Kremlin’s ruler need say l’état, c’est moi. China is certainly authoritarian, but it is a one-party state of precisely the sort Putin has failed to build.

One characteristic of paternalistic regimes is that they rule through fear and humiliation — remember the refrains from the streets of Tunisia and Egypt about people protesting to regain their dignity. That is being lost in Russia. One analyst, who has always spoken to me freely before, asked not to be quoted. When I asked a Russian businessman who was traveling in Europe what his friends back home thought, he was shocked by my naïveté: Kremlin politics, he explained, was no longer an issue it was safe to discuss on Russian telephones.

The sense of humiliation is even greater. “A lot of my friends are very disappointed that the private decision of two friends can determine the fate of their great and huge country,” one oligarch from the former Soviet Union told me.

Most humiliated of all was President Medvedev, who was required to announce his abdication from the Kremlin himself. “Medvedev is now the ultimate symbol of weakness,” Krastev said. “The liberals now hate him more than they hate Putin.”

Don’t, however, expect Western business to complain. When it comes to dealing with governments, especially foreign ones, chief executives love one-stop shopping, and that’s one thing a personalistic dictatorship provides. As one European chief executive told me, “We applaud this candidacy. Putin has been supporting industry in a way that is remarkable.”

Another thing Western chief executives like about dealing with dictators is presumed stability. That’s not entirely a myth — look at Ukraine to see how turbulent a post-Soviet state can be when it experiments with democracy — but it isn’t totally true either.

Paternalistic regimes can be very strong, but they are also very brittle. They have two great vulnerabilities. The first is money. Fear and humiliation are important tools for a neo-patrimonial strongman, but he needs cash, too. A Russian economist I spoke to calculated that if the price of oil were to fall below $60 a barrel, and stay there, Putin’s reign could soon be imperiled.

The second is succession. The central problem with a regime built on one man — and a reason Putin tried to institutionalize Russian authoritarianism — is that it has no mechanism for transferring power.

“For this type of regime, the only succession is that you clone yourself,” Krastev said. “In 2008, Putin wanted to convince us that he, like Yeltsin, could retire to the dacha. Now, there is no dacha for Putin anymore. He must die in the Kremlin.”