US Army General Martin Dempsey was sworn in as the new US Joint Chiefs of Staff on Friday after Admiral Mike Mullen retired from his post.
Speaking at a ceremony outside Washington, the retiring admiral said he believed the security transition in Afghanistan would be the biggest challenge for Dempsey in the coming years. US troops are scheduled to turn over security responsibilities to Afghan forces by 2014. Dempsey, however, has said the biggest challenge going forward is the US national debt and the security threat it poses to the US.
