Pickman's model
Starry Wisdom
It's simple - Israel decided that Gaza was going to say quiet, because they wanted Gaza to stay quiet - because they wanted to divert resources to the West Bank, and secondly because Hamas had got the measure or Israeli int gathering and fed it what it wanted to hear.
The first bit was by far the most important: Israel had decided that Hamas didn't want to go to war, so anything it saw in Gaza was not Hamas preparing for war.
For anyone with an interest in history, if you change the words Israel, Gaza, West Bank ,and Hamas to the UK, Falkland Islands, Europe and Argentina, you get an exact replica of what happened in 1980-1982...
loads of stuff on the internet on deception, if only you look. a quick search turned up military manuals, bibliographies and this 'deception maxims' document from the cia. and if you're somewhere where you've a load of time on your hands, like most people in gaza, then it's no surprise that sooner or later people decide to take advantage of the zionists' complacency