And the rationale is explicated:

The IDF Spokesperson's office issued a statement, emphasizing that this stage of the operation will further the goals of the eight-day offensive as voiced by the IDF until now: To strike a direct and hard blow against the Hamas while increasing the deterrent strength of the IDF, in order to bring about an improved and more stable security situation for residents of Southern Israel over the long term.

How does just war theory defend the deaths of many innocent civilians as a means to increase "deterrent strength"? But notice also the modesty of Israel's apparent war-aims: a more stable security situation for residents of Southern Israel over the long term. They're not optimistic about ending those rocket attacks, are they?

(Photo: Israeli Defense Force troops prepare to mobilize on January 3, 2009 on the Gaza/ Israel border. The IDF have this evening launched a ground offensive in Gaza in an attempt to take control of Hamas Qassam rocket launch sites in the region. By Uriel Sinai/Getty Images.)