How not to prepare for an alien invasion

This is the most ridiculous book I've seen in quite some time: An Introduction to Planetary Defense: A Study of Modern Warfare Applied to Extra-Terrestrial Invasion by Travis S. Taylor et al.

Book description

"This book describes a serious look at defending the planet in the event of an extra-terrestrial invasion. Travis Taylor, et al, have written the definitive book on the defense of earth against a potential alien incursion. Whatever your beliefs on the subject...the book also serves as an important primer on the potential future of warfare on every level. It is tightly grounded in current day realities of war and extrapolates thoughtfully but closely about future potentials. It should be on the reading list of anyone who is serious about national security and the future of war."

The authors believe that there is a "high probability" that one or two intelligent alien species visit Earth every century. They also reject Carl Sagan's famous assertion that advanced space-faring civs have by necessity (i.e. selectional processes) advanced beyond the need for war. "It's a wonderful idea that has no basis in reality," claims Taylor.

Consequently, they feel that the world, or more specifically "America," needs to be on the ready. They advocate asymmetric warfare to combat the extraterrestrials. The authors argue that the likely technological imbalance would force defending forces to adopt guerrilla-like tactics -- warfare along the lines of what is currently being experienced by troops in Iraq and Afghanistan. "[I]if we were attacked by aliens, this is our best defense," writes Taylor.

Post-Singularity warfare

There is so much wrong with all this that I don't know where to begin. Their line of argumentation seems to belong in the 20th century.

The idea of the United States defending the planet with guerrilla tactics reminds me of one of the most absurd films of all-time, Independence Day. In this movie, America experiences a supreme ass kicking until the alien invaders are thwarted by the Fresh Prince and his Apple Newton (remember those?).

Okay, time for a 21st century reality check. And let me put it this way: setting aside hand-waving dismissals of the Fermi Paradox (and that's a BIG caveat), if an advanced space-faring intelligence were to arrive at Earth with hostile intentions, their attack would be over before we could say, "E.T. phone home."

Specifically, I'm imagining a post-Singularity machine intelligence with access to artificial superintelligence, advanced robotics, genetically designed phages, and Drexlerian nanotechnology (if not femtotechnology). It would be like the Terminator and Matrix worlds on steroids. And that's if they want a planet to recover; the use of anti-matter weapons would make quick work of our planet should they want to destroy it. Alternately they could set the atmosphere aflame using grey-goo nano. Or how about robotic locust swarms, autonomous hunter-killers, and neurowarfare?

Moreover, malevolent ETIs wouldn't even need to visit the Earth -- they could send their forces by proxy in the form of Von Neumann probes, or what has also been dubbed berserker probes. These are self-replicating space-craft that could conceivably reproduce and travel across the Galaxy at an exponential rate. These devices could carry a number of nasty weapons with them for their attack.

As an aside, the theoretical prospect of berserkers poses a conundrum that's related to the Fermi Paradox. Any malevolent or misguided advanced intelligence could spawn a fleet of these probes to sterilize the Galaxy in fairly short order. That said, we clearly don't live in a sterile Galaxy as witnessed by our ongoing existence. We appear to live in a Galaxy that's devoid of berserkers for non-obvious reasons.

So, my advice on preparing for an alien invasion?

Simple: don't bother -- you won't even know what hit you.