In a gift to the election-weary U.S. news audience, the British National Archives has released 1,500 pages of formerly secret government documents relating to UFO sightings. The one incident that has drawn the most attention so far is an account of U.S. aircraft being ordered to shoot down an unidentified flying object over the English countryside. From a Reuters article covering the release:

In a written account, Torres described how he scrambled his F-86 D Sabre jet in calm weather from the Royal Air Force base at Manston, Kent in May 1957.

"I was only a lieutenant and very much aware of the gravity of the situation. I felt very much like a one-legged man in an ass-kicking contest," he said.

"The order came to fire a salvo of rockets at the UFO. The authentication was valid and I selected 24 rockets.

"I had a lock-on that had the proportions of a flying aircraft carrier," he added. "The larger the airplane, the easier the lock-on. This blip almost locked itself."

At the last moment, the object disappeared from the radar screen and the high-speed chase was called off.

In my initial research sweep for this site, I came across more than a few serious analysts who were considering the utility of space weapons against potential extraterrestrial hostiles. I wasn't sure what to do with the argument but added a few quotes that were especially notable because of the author (ex. renowned strategist, Colin S. Gray) and lumped the ET threat with the asteroid threat to give it a little more credibility as an argument. As an example:

Now, because the issue has legitimately been raised in the news cycle (well, tangentially) and because I too, am more than a little fatigued of election coverage, I would like to address the burning question: Does the threat of extraterrestrial invasion justify a robust space weapons program?

Short answer: probably not, and in some cases it could possibly invite attack. There is a whole subset of the UFO literature examining the connection between the U.S. missile defense / anti-satellite weapons program with some even claiming the U.S. testing of an air-launched ASAT was an early anti-UFO weapon. However, as the anecdote above (and the first half of any alien invasion science fiction movie) illustrates, it is unlikely that our primitive missiles would do anything more than annoy any civilization capable of traversing interstellar space. The authors of the site "Exopolitics" further warn that our aggressive space power strategy could threaten relations with peaceful civilizations. (example: "Using Space Weapons Against Extraterrestrial Civilizations."

Another possibility (from the opposing Realist school of international/interplanetary relations) is that existing civilizations will ignore us until we show ourselves to be a threat to them, possibly by developing space weapons. Two American scientists, Charles Pellegrino and George Zebrowski writing in their novel The Killing Star, came up with this theory of a "Relativistic Universe" when they realized that a spaceship that could achieve about 90 percent the speed of light (or 600 million MPH) could annihilate any planet in its path. Given this grim but factual reality, civilizations would be compelled to pre-emptively strike against emerging space powers to avoid their own destruction. As Adrian Berry puts it

Such a civilisation would be obsessed with one question that would seem terrible to it: `Is any other civilisation, beside ourselves, likely to develop the matter/antimatter engines that would enable them to travel at hundreds of millions of miles per hour? If so, we must not wait. We must destroy them now, because if we don't they might one day destroy us. It may be the law of the jungle, but so be it. We must kill or expect to be killed.' The most frightening part of the hypothesis is that a relativistic civilisation would not be evil, as we understand the word. Its inhabitants would only be coldly calculating. They might suspect that other beings were capable of friendship and generosity, but they would not dare to believe it. Once they possessed deadly weapons they would feel compelled to use them.

Probably how we might also react if a previously peaceful species suddenly gained sentience on Earth. O.k. enough fun for now, even two weeks before the election, things are getting interesting again with the continued evolution of the U.S. spy satellite program and China's microsatellite proximity operations. I'l get serious again ;)