Inflation has surged in Russia as sanctions ratcheted up the price of imports. Russia is assembling an economic relief package equivalent to tens of billions of dollars to soften the blow of Western sanctions and shield its population from the financial fallout of President Vladimir Putin’s war in Ukraine . Moscow’s measures—which focus on aid to struggling individuals and businesses—are unlikely to prevent Russia from spiraling into its sharpest slowdown in decades, economists say. But they show the deep pockets available to the Kremlin to tide the population through the disruptions of the wartime economy. Since the Feb. 24 invasion, Mr. Putin has signed several rounds of anticrisis legislation and ordered an emergency increase in payments to pensioners, state employees and the needy to compensate for surging inflation. He has also backed state-subsidized loans to companies battered by sanctions. […]