I don't think the Russians appreciate a U.S. presence in the Baltic Sea area. First it was a SU-24 making a close pass on a destroyer, then it was a recon plane being harassed by a SU-27, now another recon plane was harassed by a SU-27. This time the SU-27 actually did rolls around the plane.
It's going to be a repeat of the China situation. Eventually the two planes will collide. I doubt the outcome will be as favorable as last time though. Though that was an amazing feat of aviation managing to get that P-3 out of an inverted dive without ripping off the wings after the Chinese pilot collided with the nose.
In all reality, it is probably useless intell that this aircraft is collecting. And of course "We don't want to look weak in front of the Russians!". Is there any way to avoid getting a bunch of Americans killed on a wingless recon plane and still save face?