The story
In allusion to the Great Wall of China. First used in March 2015 by US Admiral Harry Harris, commander of the Pacific Fleet.
Etymology from Wiktionary, CC BY-SA 4.0.
Great Wall of Sand
Today it means: A series of uniquely large-scale land reclamation projects by the People's Republic of China in the Spratly Islands, South China Sea from late 2013 to late 2016. Full definition →