This happend after they(Israel) withdraw their presence in Gaza.
The normality of Palestinian life has also been jeopardized by intense episodes of Israeli assault since the disengagement, prolonging the economic crisis with unfavorable periods of unpredictability. The chronology of military events cannot be interpreted in isolation and should be considered in coordination with two significant events that occurred soon after the disengagement plan was implemented, namely the ascent of Hamas to the Palestinian Authority in January 2006 and the cross-border abduction of an Israeli soldier by Hamas-affiliated militants the following summer. Over the course of five months, Israel launched Operation Summer Rains, firing 200-250 artillery shells into Gaza daily and launching over 200 air strikes, which killed over 400 Palestinians combined. [19] In contrast, Palestinians fired an average of nine homemade rockets into Israel daily during the same period, killing four Israeli soldiers and six Israeli civilians. [20] Despite a tentative ceasefire in December 2006, fighting continued sporadically and eventually culminated in Israel's reinvasion of the strip in May 2007 and the persistence of almost daily incursions ever since. The recent decision to brand the Gaza Strip an "enemy entity" would have been laughable, had it not so appallingly revealed Israel's intentions for the Gaza Strip---Kris Petersen, The Electronic Intifada, 24 November 2007
See w/c party caused more damaged on civilians?
For one abducted Israeli soldier the cost is too much.