Author: Atarah al'Norahn
Mosk is a character from stories that are told by gleemen, such as Thom. Apparently, he was a giant with a Lance of Fire that could reach around the world (TEotW, Ch. 4). The stories about Mosk come from the Age before the Age of Legends (TSR, Ch. 20).
According to the website "Seven Spokes", Robert Jordan has confirmed that Mosk refers to Moscow, Merk to America, and the spears of fire with which they fought to nuclear missiles (http://www.sevenspokes.com/chronology/1st.html).