Suppose The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger and stronger, are collectively referred to as the Great Wall. The main line of the Great Wall stretches over 13,000 miles.
Can we infer that "The Great Wall of China was built to protect China from attacks by nomadic groups from the south"? Yes, no, or maybe?