During the war, Portugal faced increasing dissent, arms embargoes and other international sanctions. Merchant guilds enforced contracts through embargoes and sanctions on their members, and also adjudicated disputes. The coalition also called for arms embargoes and targeted sanctions. Western countries imposed arms embargoes on China. Arms embargoes imposed by several Western countries made the situation more difficult. Article XI addresses the quantitative restriction provision which involves the dispute over embargoes vs. tariffs. Thanks to trade embargoes and the blockade, imports into Germany declined by 80 per cent. A crisis can develop due to industrial actions like union organized strikes and government embargoes. Japan's dependence on imported oil made the trade embargoes especially significant. Several countries, including the Soviet Union and China, placed arms embargoes on Iraq. Vietnam was also subject to trade embargoes by the U.S. and its allies. The Netherlands send the submarine to upheld trade embargoes off the coast of Yugoslavia. Companies must be aware of embargoes that apply to the intended export destination. See United States embargoes for a list of affected countries. Research in this field intensified in the 1980s following the oil embargoes of the 1970s.