How did God plan to use Israel to reach the pagan nations?
God planned to use Israel as a funnel to reach the pagan nations. He intended that through Israel He would bring the nations of the world into a knowledge of their God. Israel was given this opportunity and option, but the context notes they rejected it.
Les explains that after the Tower of Babel, humanity had largely succumbed to idolatry and pagan worship. God called Abraham and made a covenant to create a special nation, Israel, and give them a land. The whole object was that He would use Israel to funnel back into the nations of the world and bring them into a knowledge of their God. That was their opportunity and option, but they rejected it.