Throughout the history of Israel, armed force has been the usual instrument of policy, not surprisingly for a military state. It's an area in which the state holds all the cards, a method that has proven very effective in the past and a big reason that the current non-violent protests in the occupied territories (and in Israel itself) are a frustration to the Israeli government - the use of force against the non-violent is counterproductive and only raises the level of outrage against the state, not just within Palestine but worldwide.
So it isn't surprising that an effort would always be made to turn events into such as would justify the use of military might.
It has now been two years since the Cast Lead operation conducted by Israel against Gaza in which several hundred civilians died and an incredible amount of damage was done, most of which has yet to be repaired by a people under lock-down.
Israel claims that it was the rocket fire from HAMAS (always in capitals because it is an acronym) that forced Israel to respond. When I participate in demonstrations against what Israel does, passersby sometimes will say, "what about the rockets?" The public perception in the U.S. is, as is almost always the case, the story of justification that Israel puts out.
As we all know from life experience, details often betray the story line for any situation, but they are often buried and boring. With that in mind, you should take a look at this short article on the rocket fire situation that took place prior to Cast Lead. It appears Israel was looking for a reason to attack while restrained by a cease-fire with HAMAS, so broke the cease-fire with a small raid unlikely to appear in the press in order to bring a response that could be used as required.
It should be noted that because there are several armed groups of Palestinians that oppose Israel, any action by any one of them can be blamed on the Palestinians as a whole with the result of collective punishment; the political divisions with the Palestinian movement are tailor made for the use of Israel to punish at will because all can be blamed for what anyone does.
FYI: Maureen Murphy, who is the managing editor of the Electronic Intifada (in which the above article appears), was one of those served by the FBI with subpoenas to appear before a grand jury, and who has refused to testify.