When we read Jonah, our attention is naturally focused on the fascinating character of the prophet. He disobeys and flees, only to be cast a watery grave. He learns his lesson enough to obey the next time, but he’s awfully surly at the end about the withered plant.
Insofar as a bigger picture emerges, it is sometimes seen to be an early form of Semitic nationalism or ethnic pride. Jonah does not want to share the riches of Israel with the Gentiles.
True enough, all that. But I think the narrative thrust is actually elsewhere. Jonah disobeys and goes onto a ship in the opposite direction. The result: Sailors convert. Then he obeys and preaches in Ninveh. The result: Nineveh converts. Regardless of his actions, Yahweh does His will with the Gentiles. He is determined to fulfill the Abrahamic promise, and He will do it regardless of Israel’s participation.
The question at the end of the book seems is like a sermon at a missionary conference. The message is: God is on the move; the nations are being converted; are you going to sit there pouting or you going to get caught up in the wind of the Spirit?