Trajanus
Paranormal Adept
The year was 1969 and blacks in america had barely been accepted with equal rights.
Imagine having to deal with an ET issue at that moment... not to mention the religious context of the times.
Vietnam was a bigger issue.
This is year 2011... and we're about to face global cascading economic failures. And maybe a nuclear Iran...
I don't think the latter is such a big deal. Israel and the US have overwhelming deterrent capability. There's always some kind of earthly problem, so I don't think that's the key reason. The alien agenda if known, may be to grim to reveal if we can't yet do much about it.