1)
What is "Nadamu"?
1.
Rashi: It is an expression of destruction, like "Hadimanu", "v'Nidmah Sham" (8:14).
2.
Radak, Malbim: Will be cut off. This is like "Gam Madmen Tidomi" (48:2).
2)
What are "Ne'os ha'Shalom"?
1.
Radak, Malbim: They are pastures where they used to graze in peace. This is a metaphor for their cities and Medinos.