Splits on Russia in German left risk undermining Merkel

By Madeline ChambersBERLIN (Reuters) - Germany's decision to expel Russian diplomats has split the Social Democrats (SPD), Chancellor Angela Merkel's coalition partner, undermining her tough stance on Moscow just two weeks into a new government.Berlin is sending four diplomats back to Russia, joining other European states and Washington in a concerted response to a nerve agent attack on a former Russian spy in England which Britain blames on Russia.Moscow denies any involvement.