Iliescu served as minister of youth in the late 1960s, when Romania had a reputation as being one of the most independent-minded, Western-leaning countries of the Eastern Bloc. Romania earned this reputation primarily for denouncing the Soviet invasion of Czechoslovakia in 1968. Nicolae Ceausescu, the party leader, did not sustain his pro-Western leaning for very long, however, and beginning in the early 1970s, he became increasingly authoritarian, establishing something of a personality cult similar to those of Stalin or Mao. He began hanging posters of himself in every building and cracking down on all forms of dissent. In 1971 Iliescu made clear his disapproval of the direction Ceausescu was taking and was removed from his post as secretary of the Central Committee. Iliescu was sent to the provinces to lead district-level party organizations and in 1984 was removed from the party outright.
From 1984 until the events of 1989, Iliescu returned to Bucharest and headed a publishing house specializing in technical literature. As opposition to Ceausescu formed in 1989, Iliescu used his old connections to rise into the leadership of one of the largest revolutionary movements, the FSN. Iliescu became its president on 22 December of that year, just as the Ceausescu regime was in its final hours. He formed a transitional government in opposition and after Ceausescu was killed, the FSN formed the National Salvation Front Council, which in those chaotic days established itself as the most legitimate authority in the country. It called for national elections in 1990; and Iliescu was elected to the presidency by a huge margin. Once in power, however, Iliescu and the FSN did little to distinguish themselves from the regime they had replaced. Later that year Iliescu and his council brutally repressed student-led demonstrations against the new government. It did so by bringing in pro-Communist miners from the provinces to attack the students, allowing the government to claim it had nothing to do with the conflict. No one doubted, however, that Iliescu had arranged for the miner-led suppression.
Iliescu served as president from 1990 until 1996. This era in Romanian history was marked by great political confusion. Parties formed and disbanded; leaders switched parties and stances; the former Communists changed their names several times; a new Constitution was approved; and two prime ministers came and went under differing coalitions in Parliament. The FSN split during this period into two factions, each of which changed its name twice. The faction led by Iliescu had by 1993 become the Party of Social Democracy of Romania (PDSR). In 1996, Iliescu lost presidential elections to Emil Constantinescu, leader of the reformist Democratic Convention (CDR). No party won a majority of parliamentary seats, however, so Constantinescu was forced to govern with an unstable coalition. His presidency saw great economic decline and very little social stability. Many Romanians feared that the political and economic conditions had deteriorated so badly that the West was ready to write the country off as one of the completely failed post-Communist states, in league with such impoverished countries as Belarus, Ukraine, and Moldova. In the 2000 election, Iliescu campaigned on these fears, pointing out all the failures of the Constantinescu presidency and promising to institute real reforms and win for the country membership in the European Union (EU) and the North Atlantic Treaty Organization (NATO).