 It was announced in a briefing in Moscow by Secretary Ernesto Abella, and will be in effect until December 2019.Martial law was introduced in communist Poland on December 13, 1981 by General Wojciech Jaruzelski to prevent the democratic opposition from gaining popularity and political power in the country.Thousands of people linked to the Solidarity Movement, including Lech Wałęsa, were arbitrarily arrested and detained.