According to the doctrine (of proportionality), a state is legally allowed to unilaterally defend itself and right a wrong provided the response is proportional to the injury suffered. The response must also be immediate and necessary, refrain from targeting civilians, and require only enough force to reinstate the status quo ante. Lionel Beehner, Council on Foreign Relations
Modern day proponents of international law certainly engage in a lot of rule-making. At least the Marquis of Queensberry provided for an on-site referee to ensure that both parties were bound by the rules.
The absurdity of the multi-cultural, politically correct assumption of the doctrine of proportionality is that it is only honored by those nations who respect the idea of civilization in the first place. Terrorists are not expected to follow the rules because they are seen as existing outside of civilization, not as members of it. Yet internationalists expect that terrorists and terrorist organizations be entitled to the protections of our world legal system, despite their not being expected to honor the same system in practice. Thus enemy combatants held at Guantanemo are believed to have "rights" but the citizens of Ashkelon and Beersheba are not entitled to the right of freedom from missile assault.
It is my contention that the Israelis' response is entirely proportional. According to the Israeli Foreign Minister's website:
1,212 rockets and 1,290 mortar bombs fired from the Gaza Strip have struck southern Israel since the beginning of the year (Jan-Nov 2008).
Of course this doesn't include the escalation in missile attacks since November. So let's assume a conservative figure of 3,000 bombs dropped on Israel since January of 2008 by Palestinians.
According to the website Jewish Issues Watchdog the AP reports that Israeli jet fighters have flown 500 bombing missions in its offensive against Gaza-based Hamas, while there have also been hundreds of combat sorties by helicopter gunships and surveillance aircraft, both manned and unmanned.
Now one must assume a ratio of about 6 bombs per sortie to achieve statistical proportionality. This seems an acceptable hypothesis to this correspondent and rounds out to about 3,000 bombs dropped on Gaza in the past year.
The fact that Israeli pilots have superior delivery systems which enable them to have effectively "better aim" seems a moot point. Approximately the same number of explosive charges have been dropped on both sides. If the Palestinians could get their hands on more accurate missiles with more explosive capacity, they would be sending them to Southern Israel on a daily basis.
The Israeli response could certainly be considered to be immediate (following the expiriation of the latest truce) and necessary and the Israelis are going to great lengths to enable civilians to avoid being harmed.
Thus the only remaining quibble over proportionality is how far ante an engaged nation is allowed to go in seeking to restore the status quo ante? Let's propose June 1967 as a starting point for negotiations.