Answer:
The government built highways that crossed through the states.
Explanation:
The Umayyads were unable to conquer the nascent Christian Kingdoms in the North which included but were not limited to: Leon, Castille, the Basque Territories, and the Catalonian Counties. In addition, the Umayyads were not able to prevent the fragmentation of their territory into the Taifa Kingdoms in 1038.
The notional barrier separating the former Soviet bloc and the West prior to the decline of communism that followed the political events in eastern Europe in 1989.