What exactly is proportionate force? Should Israel just fire up an unguided rocket for every unguided rocket which comes across?
Or perhaps unguided bombs dropped in a carpet bombing pattern across Gaza?
How about random artillery fire, and since proportionality demands ratio's and proportions, so measure the strength of the rockets and then use that size.
Sometimes I wonder why these politicians are allowed to get away with saying such fatuous sayings? Journalists should challenge them.
And more importantly, if you cannot influence the outcome, then do everybody a favour and shut up because you become part of the problem not the solution.