His audience would have cheered his rant against Moab, Aram, Philistia, Tyre and even their Jewish brothers and sisters in Judah, because this was during the divivded kingdom. In a truly brilliant maneuver he gets his audience cheering for God to punish the sins of all those people. You can imagine the people cheering Amos: "yeah! You tell 'em."
Then Amos turns to his main topic. With the same language he used against "those people" he turns his critique on his own people, the people of Israel. And the rest of the Book is focused on the sin of his people, the Northern Kingdom, Israel.
Centuries later, human nature remains the same. We are all comfortable critiquing foreigners. You can criticize any country in the Middle East, the Russians, the Germans, the French, or even the Brits, and you're safe. But criticize America, and see how quickly people respond the way the people of Israel responded to Amos. Like the people of Israel in the time of Amos who believed that they were the chosen people, we just keep telling ourselves we are the greatest country in the world. Both statements are on some level true but it does not mean that we do not need to take a hard look at ourselves.
This week as we read the Book of Amos, we need to remember that before we can remove the speck from someone else's eye, we must remove the plank from our own. This is not only true for individuals but for us as a people. Can we honestly look at our country/ our culture and be humble enough to admit where we are far from the path? Can we have the courage to hear the words of Amos addressed to us?