None of those two books are quoted - how am I supposed to know if, and to what extent, they dispute Hirst's book? The quote you do adduce, though horribly POV to be honest, in no way implies that was a casus belli for the invasion of Lebanon. As for the two other sources I added today, the book is peer reviewed and therefore is fit for Wikipedia. The editorial is syndicated in a mainstream source, The Independent, and has an extremely notable author when the subject is Israel, Palestine and Lebanon: Robert Fisk. It more than surpasses Wikipedia's notability standards. And I just added a third book about Israel's military history.