What does Isaiah 17:3 mean?

The fortress will disappear from Ephraim, and Damascus will lose its kingdom. What's left of Aram will fade away, just like Israel's glory did. That's what the Lord of all says. Isaiah 17:3 - Modern Text Bible

(Both Israel (Ephraim) and Syria (Damascus) will lose their power and prestige. Their downfall is certain, decreed by God.)