 In February 1885, under diplomatic pressure from China, Britain invoked the provisions of the 1870 Foreign Enlistment Act and closed Hong Kong and other ports in the Far East to French warships.The French government retaliated by ordering Courbet to implement a 'rice blockade' of the Yangzi River, hoping to bring the Qing court to terms by provoking serious rice shortages in northern China.The rice blockade severely disrupted the transport of rice by sea from Shanghai and forced the Chinese to carry it overland, but the war ended before the blockade seriously affected China's economy.