Union to interpret the agreement as it wished and they may have intended to never actually transfer any. In 1990 the agreement ceased to be in force following a year's notice period in the agreement, and the nuclear weapons were probably then removed from Poland. Polish thermonuclear weapons program Apart from Soviet warheads designated to deploy within Polish military in case of war with NATO, it is believed that Polish authorities attempted to develop thermonuclear weapons on its own. In 1970s a group of scientists headed by Sylwester Kaliski worked on initiating nuclear fusion using high-energy lasers. The project received considerable funds as well as personal support of first secretary of the ruling Polish United Workers' Party Edward Gierek, acknowledged with the potential military purpose of such idea. The research was dropped after Kaliski was killed in car crash in 1978, of which the circumstances remain unclear. 2022 Russian invasion of Ukraine In the aftermath of the Russian invasion of Ukraine in 2022, several Polish politicians proposed that Poland host nuclear weapons under the NATO nuclear sharing program. President Andrzej Duda has said the idea is under discussion. Jarosław Kaczyński, the leader of Poland's governing party has stated he would like Poland to acquire nuclear weapons itself, but acknowledged it was "unrealistic". References Bibliography Foreign relations of Poland Weapons of Poland Politics of Poland Weapons of mass destruction by country