A voice of trembling; rather, a sound of trembling, a sound causing men to tremble; doubtless it is "the sound of the trumpet, the alarm of war" (Jeremiah 4:19). Of fear, and not of peace; rather, there is fear, and no peace.
"Peace," as usual, means the harmony of a well ordered, secure, and peaceful community. Literally, it is wholeness; its opposite is "breaking," i.e. outward ruin and inward anguish.