Mullen: ‘I Support The President’s Decision’ On Afghanistan, ‘As Do Gens. Mattis & Petraeus’ | The right has been attacking President Obama’s decision to withdraw 33,000 troops from Afghanistan, claiming that he ignored Gen. David Petraeus’s advice. “It has been widely known that General Petraeus objected to this proposal,” Sen. John McCain (R-AZ) said on Fox News last night. However, this morning in testimony to the House Armed Services Committee, Joint Chiefs of Staff Chairman Adm. Mike Mullen said that Petraeus does support Obama’s decision. “I support the President’s decision, as do Generals Mattis and Petraeus,” Mullen said.