Oh well. However, it is a good time to reflect on the ever popular notion of alien invasion. Due to a wide variety of factors, the concept is becoming faddish in some mighty strange areas as a solution to world peace (the novel Impact by Douglas Preston) and to economic policies (Paul Krugman and his fake alien invasion proposal). Oddly enough, these ideas are almost starting to sound half reasonable.
What isn't reasonable are the various scenarios for such an invasion. Despite some recent interviews and news programs (such as the NBC Today Show story), we don't really know what the folks at the Pentagon really have up their sleeves in the event of a real War of the Worlds. Unfortunately, it is probably deeply rooted in traditional military concepts. After all, you often get a standard form of thinking from the Pentagon like you get the same type of burger from every McDonald's.
Likewise, the history of the U.S. Military cooperation with certain movies would suggest that the key concept of the film was acceptable to the brass. It doesn't mean that the government is trying to send covert messages to the audience (beyond the usual: 1. We look good; 2. We got lots of neat equipment; 3. Don't worry - if anything happens we can handle it; 4. Why not join?). But it does mean that the core ideas are considered half OK.
So certain Hollywood movies do suggest some of the thinking and basically, it all seems to be rooted in the central concept of total full frontal attack as found in such classics as Earth vs. the Flying Saucers and War of the Worlds. Lots of aliens with lots and lots of ships that come screaming in until it becomes a pitch battle waiting for something that tips the war to Earth's favor.
From a film producers viewpoint, this is the way it ought to be. Major tourist sites get blown up, mass carnage and speculator displays of destruction followed by a nice moral message and a sweet surge of optimism about the human spirit. But to be honest, I doubt if an alien invasion would ever happen in this manner. For one thing, the sheer cost in material needed for a global invasion (even of a smallish planet such as ours) would have to be mind boggling. Even with superior weapons, alien invaders would have to expect a protracted and costly fight.
Of course this type of invasion is also remarkably human in its planning. Presumably this is how we would do it...oh yeah, we are not talking about humans are we. For all I know, we could be talking about methane breathing jellyfish critters from a moon of Saturn.
Which is why I would argue that the real starting point for exploring alien invasion (at least in theory) is best found in the TV scripts of the British writer Nigel Kneale. Especially the four parts of the Quatermass trilogy (long story but it is sort of a four part trilogy).
The most important of the original stories would be Quatermass II and Quatermass and the Pit (better known in the U.S. by the title of Five Million Years to Earth). Quatermass II answers the question about methane breathing life forms (most likely they would deal with invasion through a radical change of our atmosphere - which would deal with the human issue pretty quickly). As for Quatermass and the Pit, well if you have read Nick Redfern's book Final Events then you can kick back and watch the so-called Collins Elite's worse nightmare. Even more bizarre, Kneale has an incredible skill at making the fantastic seem strangely logical and highly plausible.
Along with the work of Nigel Kneale, I would also highly recommend the novel The Midwich Cuckoos by John Wyndham. This tale of an attempted invasion involving a small band of alien-hybrid children is profoundly precise, rational, and deeply disturbing. Good grief, it also sounds modern. But if you cannot find a copy of the book, the original British film version titled Village of the Damned does a good job of conveying most of the book's key points (minus the references to Hegel). Skip the American version. It is extremely weak.
This is merely a short list, but these would be the key works to start any serious study on the subject. I just hope the Pentagon is playing attention.