In verses 1 and 14, Amos addresses the nation's leadership about the way they were living. Chief means "first." They felt Israel was the chief nation on earth, and no other could withstand it. But God says the leaders of Israel were complacent, "at ease," and the nation was following their examples.
The common Israelite looked to people of wealth, power, and influence for models of their own behavior, and they saw self-indulgence, unfounded pride, moral degeneracy, and self-satisfaction. Another nation, the real "first nation," would show Israel its true state by destroying it. Israel would be attacked from Hamath in the north to the Arabah in the south.
John W. Ritenbaugh
Prepare to Meet Your God! (The Book of Amos) (Part Two)