Ever since Israel unilaterally left Gaza, in 2005, giving the Gazans the chance to forge a better future on their own, the Gazans haven't been. Part of not doing has been to shoot so many rockets and mortar shells at Israeli civilians that the town of Sderot is slowly disintegrating. The Israeli government has been playing a cynical game whereby so long as it's "only Sderot and vicinity", and the number of casualties is small (and note: small is not non-existent), the response is gaged so as not to cause major turmoil. Should this change for the worse (the decision being 100% in the hands of the Gazans), Israel will have no choice but to escalate its use of power. (The option of peace-making is not even theoretically possible when you're dealing with the Islamic Jihad organization, a gang of extremists that make even Hamas look, well, less awful).
So the discussion rages, the rockets land, and this week the IDF escalated, mostly, at this stage, by hunting down the Jihad men. The BBC reports this morning, and I quote: "The attack [on Harazin's] car killed an Islamic Jihad associate". Harazin himself, we're to understand, was a senior associate.