The Russian currency, which was trading at about 84 rubles to the dollar on Feb. 23, the day before President Vladimir Putin launched the attack, had plunged roughly 70 percent by March 7. As of Wednesday, the ruble was nearly back to its prewar level. That’s partly because a surge in oil and gas prices — commodities that were explicitly carved out of the initial sanctions — has boosted Russia’s energy revenue.

“The strength in the ruble is reinforcing the argument for those who think that we need to take greater steps on the energy side,” said Rachel Ziemba, an adjunct senior fellow at the Center for a New American Security. “It’s definitely increasing that political pressure.”

Some current and former Treasury officials, foreign exchange traders and sanctions experts say the ruble’s rebound doesn’t necessarily mean the West’s economic weapons are losing their punch. While there may be reason to escalate sanctions, the currency’s comeback primarily reflects the extraordinary steps Russia’s central bank has taken to stop the ruble’s freefall, they say. It is not a sign of an improvement in the Russian economy or in Putin’s hand.