That so well equipped an army should flee seems incredible. Hence the astonished question, Wherefore have I seen, etc.? literally, Why do I see (that) they (are) dismayed, turning back? And look not back.
With the object of rallying the scattered forces. For fear was round about. It is a pity that the Authorized Version has not kept one uniform rendering for this favourite expression of Jeremiah. In Jeremiah 6:25 (see note) it is translated, "fear is on every side" (Hebrew, magor missabib).