Hosea, a contemporary of Isaiah (for most of his ministry) and Amos (in his earlier years) was the Jeremiah of the Northern Kingdom. His main target was the Northern Kingdom, yet his message was for the people of God.
When Solomon died, Jeroboam rebelled and plunged the Northern Kingdom into a prosperous but idolatrous separation. After two centuries of abandoning their heritage, God sent Hosea to present His indictment and declare that He would use their enemies as His judgment.
Amos was sent to Israel at a time when the nation feels militarily secure and prosperous, yet is turning to idolatry and abandoning their heritage. Misplaced confidence; false sense of security; abandonment of the greatness of their nation... (Sounds familiar, doesn't it?) In many ways a complement to Hosea, this perspective on the plight of Israel parallels the predicament of our country today.