Jacob J. Lew, the U.S. Treasury secretary, urged Germany and its European partners to take even bolder steps in terms of banking reform. In a news conference with German Minister of Finance Wolfgang Schaeuble, the Secretary gave the Europeans credit for making “significant progress” in this domain. But he stressed that beyond salvaging damaged banks, Washington would like Europe to head off trouble by requiring “backstops,” higher capital reserves for banks that would enable them to better withstand crises