What did Amir mean when he said "Islamabad was the city Kabul could have become someday"

Kabul was a city of danger and destruction...... in a different time and place, it could have become a beautiful city.

If Peshawar was the city that reminded me of what Kabul used to be, then Islamabad was the city Kabul could have become someday. The streets were wider than Peshawar's, cleaner, and lined with rows of hibiscus and flame trees. The bazaars were more organized and not nearly as clogged with rickshaws and pedestrians. The architecture was more elegant too, more modern, and I saw parks where roses and jasmine bloomed in the shadows of trees.