File photo of Martin Dempsey. Martin Dempsey assumed the role of top US commander overseeing both the Iraq and Afghanistan wars Friday, replacing William J. Fallon as the head of the US Central Command (Centcom). 

Martin Dempsey assumed the role of top US commander overseeing both the Iraq and Afghanistan wars Friday, replacing William J. Fallon as the head of the US Central Command (Centcom).

Although it is unclear whether the new assignment is temporary or permanent, Dempsey will be in the position for some time, according to wire and TV reports.