The missile can have a trajectory that is for the most part ballistic, but the guidance does not end once the boost phase is over. Post boost phase guidance can range anywhere from a MIRV bus making course changes as it releases individual warheads (Trident, Minuteman III, SS-18) to terminal guidance (Pershing II). The Iskander may have such, possibly using the GLONASS (Soviet/Russian version of our GPS).
That’s pretty scary.
Big change from plopping one out of a plane in ‘45 :)