It appears to me that the goal of IHS, at least in the 20th and 21st century, has been to divide us to the point where it could overtake our global governments, and force a stand down to a battle which I believe was being waged by the USA and USSR together towards the end of the Cold War. I believe this alien force not only made itself known, but its true intentions, to keep us locked to this planet became apparent. At this point, both sides of the Cold War began detonating high atmosphere nuclear weapons under the guise of testing. It is my belief that they were not testing, but were rather trying to destroy a machine which they had deduced was invading the minds of government employees. It seems they have acquiesced to this desire, and international space exploration efforts have all but stopped, all eyes shifting to a financial crisis which appears to be manufactured in order to eliminate the debt of these governments.
This force is limited, and while its weapon is powerful and fearful, there are most likely countermeasures known to the CIA and related bodies. In addition, pure growth, on a galactic scale, would most likely weaken its ability to influence human events... in short, agreeing not to colonize space is equivalent to surrendering our civilizations future and hegemony.