Say what you will about Rumsfeld et. al., at least he wasn't worrying about aliens:

UFO sightings and alien visitors tend to be solely the reserve of sci-fi movies.

So when a former MoD chief warns that the country could be attacked by extraterrestrials at any time, you may be forgiven for feeling a little alarmed.

Just because the guy once held high office doesn't mean he's not a complete nutter. The ultimate truth is, if an alien society builds a technology base capable of interstellar flight, it will ipso facto have a technology base capable of slapping us around like the uppity chimps we really are. Seeing it coming will just mean we get to party before they arrive.

"Insert obligatory Simpsons 'I, for one' reference quote here..."