Barack Obama’s disinclination to intervene in the Mali and Algerian gas field crises is a mark of his evolving isolationist policy for the United States.DEBKAfile:  Even though the US homeland may not be in immediate peril from the two episodes, Al Qaeda’s interconnecting tentacles cannot be ignored:  Seven years ago on July 7, jihadist suiciders blew up London trains and a bus with explosives provided by the very Al Qaeda cells of Sahel Desert which today occupy Mali and this week struck the Algerian gas field.