What does proportionality mean?

This from Dore Gold, formerly Israel's ambassador to the UN, writing in the Los Angeles Times ("Israel's Doctrine of Proportionality in Gaza"):

It should be recalled that proportionality in international law has a very specific meaning: It is the calculation a military commander must make as to whether the military advantage to be gained by the use of force is greater than the probable harm that may be inflicted on the surrounding civilian population. Anyone who complains about “disproportionality” must explain exactly what the IDF should have done to neutralize the terrorist threat from Shajaiya while causing less destruction than what occurred.

What do you think, Jon? Sound reasonable?

For the rest of Ambassador Gold's article, click here.