Outline of Nahum

1:1  Author - Nahum

Judgment upon Nineveh introduced
1:2-7  The character of God
1:8-11  Judgment introduced for the first time in text
1:12-14  God speaks (text has God speak in first person on 3 occasions)

Judgment upon Nineveh revealed - possible chiastic structure.
A.  1:15-2:2  Judgment announced - cause for the oppressed people to celebrate
B.  2:3-2:10  Judgment described
C.  2:11-12  Judgment compared to defeat of a lion, a symbol of Assyrian culture
D.  2:13  God speaks
E.  3:1-4  Judgment described
D'  3:5-7  God speaks
C'  3:8-11  Judgment compared to defeat of Thebes, a city the Assyrians destroyed
B'  3:12-17  Judgment described
A'  3:18-19  Judgment announced - cause for Assyrians to mourn

UPDATE: The other day (May 6, 2013), I was visiting the NET Bible. I clicked on Nahum and looked at "Constable's Notes." He cited an outline that looked very much like what I wrote above. He footnoted the item to two works: Robert B. Chisholm Jr., Handbook on the Prophets, p. 428. See also Gordon H. Johnston, “A Rhetorical Analysis of the Book of Nahum,” (Ph.D. dissertation, Dallas Theological Seminary, 1992) for a thorough analysis of the book’s structure. Its nice to know that someone else has seen the same literary structure!