The New York Times reported that two prominent legal scholars and rights advocates bound for an international law conference in London were blocked from leaving China on Tuesday on vague charges that their departure might endanger national security. The two men believed they could not leave because the government feared they would try to attend the Nobel Peace Prize ceremony in Oslo next month honoring the jailed dissident Liu Xiaobo.† Both men were on the list of 143 Chinese activists, academics and celebrities that Mr. Liu’s wife invited to the award ceremony.