Stream cipher preserves bit-flips between ciphertext and plaintext, which is useful property for this application. And many “military/diplomatic” ciphersystems

Stream cipher preserves bit-flips between ciphertext and plaintext, which is useful property for this application. And many “military/diplomatic” ciphersystems used in second half of 20th century have various interesting properties wrt. error correction or non-propagation. My suspicion is that these properties are built by doing MAC-then-FEC-then-Encrypt and in some cases even by relying on limited error propagation of CBC mode. If you think about it, for these applications reliability is more interesting than strict authentication as the ciphertext of diplomatic “cable” or similar thing is sent through somewhat noisy channels and often was manually handled by fallible human radio operators while active MitM was not exactly feasible attack.