Chronicles 2 ch.18 - Jewish Unity? Secular & Religious

The righteous Yehoshafat has his son marry Ahab's daughter. They launch a joint military campaign. Now Ahab is the most evil and idolatrous of kings. His wife actively persecutes God's prophets. Ahab's greatest critic is Eliyahu Hanavi.Jewish unity is nice. But should Yehoshafat be associating with this sinful king, let alone marry his son to his daughter?The prophet at the start of ch.19 severely reprimands Yehoshafat "Do you assist the sinner, and love those who hate God?" And so, today, in honour of Tisha BAv, we discuss our relationship with non-observant Jews.