A stealth aircraft is not invisible. Stealth is a passive low observability technique that alters an aircraft’s composite electromagnetic and electrooptical identities in order to be classified by an adversary as a target of no interest by blending into the background. In this paper we explain the reasons for this inability of invisibility of a modern jet fighter aircraft by employing the concepts of Stealth Entropy (SE) and Digital Steganography (DS). Our methodology is a comparison between the concepts of stealth jet fighters, low observability motion entropy and digital steganography. This effort leads to a tactical assessment of stealth aircraft. We ascertain that a stealth aircraft is very similar to a digital steganography object. Also we argue that a stealth aircraft has low stealth entropy levels. From these two points we conclude that a stealth aircraft is a radar target that is difficult to hide from air defences especially when cruising at higher altitudes. And this is the stealth aircraft paradox. Finally our work may be beneficial to air defence systems designers and their counterpart aircraft signature reduction specialists.