Interestingly, Klingons is what Starfleet was worried about just before Nero made his temporal and temporary incursion... The walla on the Kelvin
bridge includes discussion about whether the space thunderstorm would be the doing of the Klingons, and the response is a negative: the ship is "75,000 kilometers from the-".
We don't know from what, exactly, but essentially our teaser heroes are practically brushing off against something
relating to the Klingon threat! Was the ship on a mission to spy on the formidable enemy (while apparently on her way to Earth where Winona Kirk would have given birth to a son in an orderly fashion not long thereafter)? Was she being shadowed by Klingons in a classic cold war moment? Was she doing the shadowing? Had she just finished off a Klingon in battle, then been distracted by the storm? No matter what the rationale, being but a fraction of a lightsecond away from Klingons was supposed to be reassuring
at that point of time!
It's sort of a logical continuum there, then, as regards who is the real threat.