Why did the Jewish believers at Jerusalem quiet down and let Paul go back to the Gentile ministry?

Les explains that after Peter came to Paul’s defense, recalling that at the house of Cornelius God had indeed saved Gentiles, the multitude of Jews at Jerusalem quieted down. They reasoned that if this was how Peter felt about it, then they would let them go back to their Gentile ministry. Les then notes that once the Jewish believers held their peace, James—the half-brother of Jesus, not James of the Twelve, who had been beheaded earlier—moderated the meeting. James said Simeon, or Peter, had declared how God at the first visited the Gentiles to take out of them a people for His name, namely the church, the body of Christ, called out from the masses of Gentiles. In contrast to Peter’s preaching to Israel, where every one had to respond, Paul’s Gentile ministry was a calling out, a sampling from the Gentile people.