Many terror-apologists are playing loose with the facts about what happened after Israel voluntarily evacuated all Jews from Gaza, so here is a short time-line of rocket attacks from Gaza in the aftermath of disengagement:
September 12, 2005: The Israeli flag is lowered in Gaza and disengagement is over.
September 12: Rocket attack on Sderot.
September 12: Rocket attack on Yad Mordechai.
9/23: Islamic Jihad attacks Kfar Aza
9/24: Hamas attacks Sderot, 11 injured
9/25, 26, 27, 30 - At least six separate rocket attacks - followed by more...
October 2005: At least 7 rocket attacks
November 2005: At least 11 rocket attacks
December 2005: At least 34 separate rocket attacks, causing numerous injuries and much damage
January 2006: At least 27 separate attacks (most with multiple rockets)
January 25, 2006: Hamas wins the PLC elections.
February 2006: At least 55 rocket attacks
March 2006: At least 47 attacks, with injuries
April 2006: At least 53 separate rocket attacks
..and on and on. (Statistics from the Worldwide Incidents Tracking System.)
Rocket attacks occurred before, during and after disengagement; before, during and after Hamas elections; before, during and after the Hamas/Fatah unity government; through the Hamas coup, through the worldwide blockade of Gaza, through the 2007 "truce" and through the 2008 "truce." They happened while Gazans were happily employed at the Erez Industrial Park in Gaza as well as when it was shut down, they happened while Jews lived in Gush Katif and when they didn't, when the crossings were opened and when they were shut.
Qassam rockets have been shot at Israeli areas since October, 2001, and their numbers have only increased over time. To say that somehow Israeli actions are forcing the terrorists to shoot Qassams and mortars at Israel and to dismiss Israeli justifications for finally saying that enough is enough is the height of arrogance.