NSA's partnership with Israel

"And in a delicate spy-versus-spy dance, sharing takes place even with governments that are themselves important N.S.A. targets, notably Israel.  The documents describe collaboration with the Israel Sigint National Unit, which gets raw N.S.A. eavesdropping material and provides it in return, but they also mention the agency’s tracking of “high priority Israeli military targets,” including drone aircraft and the Black Sparrow missile system. "