Modern Russia is different from the Shakespeare-era Denmark, but as the Bard observed thereof, something now is rotting in Moscow. The latest sign is that one of President Putin’s oldest allies, Anatoly Chubais, today announced his resignation and decamped his country. 

Officially Moscow’s “climate envoy,” Mr. Chubais has been a far more important member of Mr. Putin’s inner circle than that title suggests. As the man who initially recruited Mr. Putin to the Kremlin, Mr. Chubais was until today’s defection one of the president’s darlings.

Mr. Chubais is, moreover, but the latest in a growing list of top players in Moscow who have either expressed skepticism about the war or were forced out by Mr. Putin, who blames them for failures in Ukraine. As is often the case with closed societies, there could be more fire than the smoke might suggest.

Russia’s wealthiest tycoon, Vladimir Potanin, warned recently that economic isolation could set the country’s economy back to the era of the 1917 Bolshevik revolution. Other oligarchs have made similar warnings. Defense Minister Sergei Shoigo disappeared from public view early in the war. Top intelligence and internal security officials were fired or arrested. 

Mr. Chubais’s departure is a “big deal,” an Israeli reporter who spent decades in Moscow as Russia correspondent, Yair Navot, says. “It may not be the end of Putin, but it shows that there is growing dissatisfaction in the ranks.”

The architect of Russia’s 1990s transformation away from an economy controlled by a Communist government, Mr. Chubais was tasked by President Yeltsin with overseeing privatization, which enriched some of Moscow’s movers and shakers. In the mid-1990s he gave Mr. Putin his first Kremlin job. 

Overseeing Russia’s largest companies after Mr. Putin assumed the presidency, Mr. Chubais remained in government and became a top adviser to Mr. Putin. Now, however, he’s announced in a letter to a group of colleagues that he is resigning his government position and leaving Russia, citing his opposition to the war in Ukraine. 

Mr. Potanin, a nickel mogul, is another top Muscovite who has been closely tied to Mr. Putin. Recently, however, he’s cited the ruinous effects of the war on the country’s economy. His warning of steps that “would take us back a hundred years, to 1917,” was made on his Telegram page, where Mr. Potanin warned of the negative results from a “global distrust of Russia on the part of investors.”

Also, according to several reports, the governor of the Russian central bank, Elvira Nabiullina, threatened to resign after the war started. Mr. Putin nevertheless managed to convince her to stay, and last week nominated her to a new five-year term at the bank’s helm. 

Unlike Ms. Nabiullina, two Russian billionaires, Mikhail Fridman and Oleg Deripaska, aired their objections to the war publicly. Mr. Fridman, a Russian citizen whose parents hail from Lviv, Ukraine, wrote in a letter to staff, “This crisis will cost lives and damage two nations who have been brothers for hundreds of years. While a solution seems frighteningly far off, I can only join those whose fervent desire is for the bloodshed to end.”

Perhaps fearing retribution, most of those who have publicly criticized the war refrained from naming Mr. Putin as the man responsible for it. The president recently vowed to cleanse the country of “scum and traitors.” Several dissenting journalists, an unknown number of protesters, and open opponents like Alexey Navalany have been jailed or otherwise made to disappear. So have some of Mr. Putin’s top military and intelligence aides. 

Defense Minister Shoigo, long considered the architect of Russian army reform, is seen as Mr. Putin’s top military adviser. He oversaw the militarily successful 2008 invasion of Georgia, the 2014 annexation of Crimea, and the Russian dominance of Syria since 2015. 

The reason for Mr. Shoigo’s 10-day disappearance from the public eye is unknown, but many in Moscow wonder if he was sidelined as Mr. Putin looks for scapegoats for failures in the war. 

According to several reports, Mr. Putin recently fired the deputy chief of Rosgvardia, the Russian national guard. Roman Gavrilov was accused of leaking secrets to the enemy. The head of foreign intelligence at the Federal Security Service, Sergei Beseda, and his deputy were reportedly fired and placed under house arrest.

Known as FSB, the service is heir to the Soviet KGB, where Mr. Putin served for decades. It is known to be particularly dear to the president’s heart. Accusing senior FSB agents of failure to foresee the war’s hardships shows that Mr. Putin trusts fewer and fewer people in his once tight-knit inner circle. 

It is unclear whether any of these developments can lead to a toppling of Mr. Putin — or indeed if such change at the top would significantly alter Russia’s policies. It’s clear, though, that Moscow’s loss of cohesion couldn’t come as good news for the man at the top.