The faltering economy is out of step with Russia’s image politically at home and abroad, as a global power in good health. Geographically, the country grew with the annexation of Crimea in 2014. But even as it meddled in elections and intervened militarily in Syria and Ukraine, the Russian federal budget has remained essentially level in real, or inflation-adjusted, terms since 2014.

Oil profits have instead gone into fattening the national piggy bank, a reserve called the National Welfare Fund. The giant account this winter reached its target of accumulating an amount equal to 7 percent of the gross domestic product, or about $125 billion.

To bolster these reserves, the government routinely incorporated into the budget tax revenue based on artificially low assumptions of the global price of oil, with surpluses saved rather than spent. The budget now balances at oil prices below $50 per barrel, while the price of Brent crude, an international benchmark, has hovered around $60.

“They were, and still are, afraid of any disturbance on the external side — be it trade wars, oil prices coming down or sanctions,” Vladimir Tikhomirov, the chief economist at BCS Global Markets, said.

With this rule in place, even short periods of rising oil prices in recent years did little to jump-start growth. Every additional dollar per barrel on the oil price adds about $2 billion to Russian tax receipts — but only becomes extra padding in the Kremlin’s cushion against a possible future downturn.

“Russia is moving from a dynamic, high growth, high inflation sort of place to something looking more like Eastern Europe,” said Vladimir Osakovskiy, chief economist for Russia at Bank of America.