It is not about time travel it is seeing paths and where events will lead to possible futures. If you drill down into some of the recent researches on quantum physics I believe that some sort of tech like looking glass is possible. I'm not bought into the "it came from aliens" story line, but I believe there is something like this tech that is involved. Military planning does not explain many of the predicted events, planning could not reach thru so many variables. It is simpler to believe that they saw it happen in the future and simply reacted accordingly.