Oleg Kashin’s cogent, depressing answer. No one.

“At the popular level, things are no better. The initially promising protests against the war have been completely choked off by the threat of prison time. Critical public statements, let alone rallies or demonstrations, are now all but impossible. Wielding repression, the regime is in full control of the domestic situation.

Instead, the factor seriously threatening Mr. Putin’s strength today is the Ukrainian Army. Only losses at the front have a realistic chance of bringing change to the political situation in Russia — as Russian history well attests. After defeat in the Crimean War in the mid-19th century, Czar Alexander II was forced to introduce radical reforms. The same thing happened when Russia lost a war with Japan in 1905, and perestroika in the Soviet Union was driven in large part by the failure of the war in Afghanistan. If Ukraine manages to inflict heavy losses on Russian forces, a similar process could unfold.

Yet for all the damage wrought so far, such a turnaround feels a long way off. For now and the foreseeable future, it’s Mr. Putin — and the fear that without him, things would be worse — that rules Russia.”