By Valentina Za MILAN (Reuters) – A ramping up of financial sanctions against Russia following its invasion of Ukraine has plunged European lenders into turmoil. The European arm of Sberbank, Russia’s biggest lender, faces failure, the European Central Bank (ECB) warned on Monday, after a run on its deposits sparked by the backlash from Russia’s invasion of Ukraine. Upending the financial sector, Western countries will exclude some Russian lenders from the SWIFT international payments system and, crucially, target the country’s central bank to stop it from using its foreign reserves. The moves…