Is Saudi Arabia Serious about Declaring War against Terror?

Saudi Arabia says it's formed a coalition of 34 Muslim nations against ISIS, other terrorist groups and their "violent ideology." The US was surprised, but calls the announcement "welcome." Pakistan, one of 34 nations named as a partner, says it wasn't even consulted. Iran, Syria and Iraq weren't included at all, raising questions about the divide between Sunnis and Shiites. Is Saudi Arabia just responding to Western critics, diverting attention from warfare in Yemen or making a real bid for leadership in collective security?