In what amounted to a multidimensional confidence-building campaign, President Petro O. Poroshenko of Ukraine tried on Friday to rally international support for his country and to maintain pressure on President Vladimir V. Putin of Russia, including economic sanctions. Mr. Poroshenko held a major news conference, gave interviews to foreign journalists, spoke by phone with President Obama and Chancellor Angela Merkel of Germany, and prepared to welcome two visiting prime ministers to Kiev, Shinzo Abe of Japan and Stephen Harper of Canada. His diplomatic activities precede a summit meeting of leaders of the Group of 7 nations that is scheduled to begin Sunday at Schloss Elmau in the Bavarian Alps, with security issues on the agenda. In each of […]