Excerpts from Books and Wikipedia
"Operation Pillar of Defense was an eight-day Israel Defense Forces (IDF) operation in the Hamas-governed Gaza Strip, which began on 14 November 2012 with the killing of Ahmed Jabari, chief of the Gaza military wing of Hamas. The operation was preceded by a period with a number of mutual Israeli–Palestinian responsive attacks. According to the Israeli government, the operation began in response to the launch of over 100 rockets at Israel during a 24-hour period, an attack by Gaza militants on an Israeli military patrol jeep within Israeli borders, and an explosion caused by IEDs, which occurred near Israeli soldiers, on the Israeli side of a tunnel passing under the Israeli West Bank barrier. The Israeli government stated that the aims of the military operation were to halt rocket attacks against civilian targets originating from the Gaza Strip and to disrupt the capabilities of militant organizations. The Palestinians blamed the Israeli government for the upsurge in violence, accusing the IDF of attacks on Gazan civilians in the days leading up to the operation. They cited the blockade of the Gaza Strip and the occupation of West Bank, including East Jerusalem, as the reason for rocket attacks." [Wikipedia]