Jamila Trindle writes: The Russian ruble is rebounding, outpacing all other world currencies against the dollar this year. The 20 percent recovery this month alone stands in stark contrast to last year, when U.S. officials smugly pointed to Russia’s plummeting currency as proof that Western sanctions against Moscow for meddling in Ukraine were working.

That doesn’t mean the sanctions no longer have teeth. But it does add another complication to Western leaders’ already difficult task of trying to forge a lasting peace in Ukraine.

Some analysts have ascribed the ruble’s upward march to the tenuous cease-fire agreement reached between Ukraine and Russian-backed separatists in February. Rising oil prices could be giving the ruble a boost, since the Russian government is dependent on money coming in from the country’s state energy giants. And yet another theory is that the ruble is not really strengthening, but just recovering to a reasonable level after plummeting too far last year.

The dramatic turnaround has prompted some investors to scramble to get back in. Bond investors, who had steered clear of Russia, are now returning in droves.

Some cautione against viewing the success of sanctions or Russia’s economy through only its currency.

While the appreciating ruble is welcome news for Russians who want to travel abroad and buy foreign goods, it may not be the sign of brighter days quite yet for the overall economy.

While oil prices have recovered somewhat, they’re still far away from the $100 a barrel that the Russian government budgeted for last year, or even the $70 a barrel Siluanov said they were hoping for this year. Russian oil sells at a slight discount to Brent crude, which traded around $58 a barrell.

European leaders struggle to hold together the fragile consensus on sanctions against Moscow, the ruble surge is giving some parts of the Russian economy a shot in the arm. Companies that borrowed in dollars, for instance, are likely breathing a sigh of relief, as their debts deflated a little bit as the ruble strengthened.

But whether or not it continues, the currency rally is unlikely to be enough to save the Russian economy, or Putin, from another round of sanctions.