Well, yes, but...
Lewis, I don't disagree with any of what you've said here, nor do I imagine does Gordon Brown. But to talk of energy security is to speak of something that is, at best, a medium-long term solution.
Gordon Brown is an economist at heart, as well a politician looking to be able to do something that will produce a measurable improvement on something that effects everybody - today.
In economic terms (and by that I mean the laws of supply and demand), what he's advocating would produce instantaneous changes on prices, not the long term changes that energy security would provide.
Course all of this is a moot point, as the current "ballistic" food prices are most likely caused by two years running of crap harvest yields. If this year is a turning point on that, we should see lower food prices next year anyway.