Well either utter incompetence of every part of military of israel, or planned to allow it to happen. They even removed most of the guards spread across the region, those who were left were often only with pistols from what I've heard. They were closely monitoring hamas training for exactly this just before it happened.

Sure, some incompetent russian fsb officer who got his place thanks to nepotism may miss that, but mosad, on border with one's mortal enemy? Give me a break, there is 0 logic and knowledge of the involved parties in such thinking.

But its expected, say soviet union went to great lengths to make state terror official and legal, justified and all by th books. Not sure for whom since all knew what chaotic terror was happening all the time and there was often no logic in who was next, but the face of the regime needed to have everything straight and square.

Anyway, those who actually care about the topic understand it well, its not some superbly hidden scheming bur rather facts in plain sight. The rest of folks simply don't care