By targeting Russia’s central bank with sanctions, experts said, American and European leaders have taken aim at what could be one of President Vladimir V. Putin’s greatest weaknesses: the country’s currency.In Russian cities, anxious customers started lining up on Sunday in front of A.T.M.s, hoping to withdraw the money they had deposited in banks, fearful it would run out. The panic spread on Monday. To try to restore calm, the Bank of Russia posted a notice on its website: “The volume of bank notes ready for loading into A.T.M.s is more than sufficient. All customer funds on bank accounts are fully preserved and available for any transactions.”Even before the sanctions were announced over the weekend, the ruble had weakened. On Monday it plunged further, with the value of a single ruble dropping to less than 1 cent at one point. As the value of any currency drops, more people will want to get rid of it by exchanging it for one that is not …
