Three and a half months into the war, it has become clear that some of the most intense barrages of sanctions ever meted out by the West — and the torrent of Western companies voluntarily leaving Russia — have failed to completely dismantle the Russian economy or spark a popular backlash against President Vladimir V. Putin.

The impact of sanctions will be deep and broad, and the consequences are only beginning to play out. Living standards in Russia are already declining, economists and businesspeople say, and the situation is likely to get worse as stocks of imports run low and more companies announce layoffs.

But the economic decline is not as precipitous as some experts had expected it would be after the Feb. 24 invasion. Inflation is still high, around 17 percent on an annual basis, but it has come down from a 20-year peak in April. A closely watched measure of factory activity, the S&P Global Purchasing Managers’ Index, showed that Russian manufacturing expanded in May for the first time since the war began.

Behind the positive news is a combination of factors playing to Mr. Putin’s advantage. Chief among them: high energy prices, which are allowing the Kremlin to keep funding the war while raising pensions and wages to placate ordinary Russians.

Ukraine’s economy has been damaged but is still functioning. Banks are sufficiently capitalized, deposits are protected by the state and A.T.M.s are being refilled, said Olena Korobkova, chairwoman of the board at the Independent Association of the Banks of Ukraine.

On the ground in eastern Ukraine, though, “very fierce fighting” continued to rage, reducing cities and communities to charred ruins, the country’s president, Volodymyr Zelensky, said in his nightly address. Ukrainians’ ability to ward off Russian troops is becoming more limited because of their unmatched weaponry and a rapidly dwindling supply of ammunition for their Soviet-era artillery.

“All these ruins in once happy cities, black traces of fires, craters from explosions,” Mr. Zelensky said. “This is probably the fastest example of the complete degradation of any state.”

In other developments:

• McDonald’s restaurants are reopening in Russia this weekend, but without the Golden Arches. After the American fast-food giant pulled out this spring to protest President Vladimir V. Putin’s invasion of Ukraine, a Siberian oil mogul bought its 840 Russian stores.

• There are signs that a partisan insurgency is executing strikes in Russian-controlled territory. Scouts working for Ukraine’s military directed artillery attacks on two Russian bases in the occupied Kherson region this week, according to a senior Ukrainian military official. Separately, Ukrainian and Russian authorities have described attacks on Russian-appointed officials by partisans.

• Russia is struggling to provide basic services to people living in its occupied territories in Ukraine, Britain’s Defense Ministry said on Friday. Kherson, the first city to be taken by Russian troops, is facing a shortage of medicines, and Mariupol is at risk of a major cholera outbreak, the ministry said.

• Western governments on Friday condemned the death sentences that court in a Russian-occupied area of eastern Ukraine gave to two Britons and a Moroccan. The men had been accused of being mercenaries for Ukrainian forces. Russia defended the court’s decision, saying the men were not prisoners of war.