Centre-left governments (1996–2001) A series of centre-left coalitions dominated Italy's political landscape between 1996 and 2001, which introduced a number of progressive reforms in areas such as social security. In April 1996, national elections led to the victory of a centre-left coalition under the leadership of Romano Prodi. The Olive Tree included PDS, PPI (the largest surviving piece of the former DC), and other small parties, with "external support" from the Communist Refoundation Party (voting confidence but not entering government). Prodi's government became the third-longest to stay in power before he narrowly lost a vote of confidence, by three votes, in October 1998. Prodi's programme consisted in restoring the country's economic health, to pursue the then seemingly unreachable goal of leading the country within the strict Euro convergence criteria set at Maastricht and make the country join the Euro. He succeeded in this in little more than six months. His government fell in 1998 when the Communist Refoundation Party withdrew its support. This led to the formation of a new government led by Massimo D'Alema as Prime Minister. As the result of a vote of no confidence in Prodi's government, D'Alema's nomination was passed by a single vote, with the support of a loyal Communist faction (PdCI) and of some centrist MPs (UDR) led by former president of the Republic Francesco Cossiga. While D'Alema was Prime Minister, Italy took part in the NATO bombing of the Federal Republic of Yugoslavia in 1999. The attack was supported by Silvio Berlusconi and the centre-right opposition, but the far left strongly contested it. It was a very important test about the government loyalty to NATO and the country's foreign policy, as it concerned the first post-Communist leader of Italy and the first military action formally outside a UN mandate. In May 1999, the Parliament selected Carlo Azeglio Ciampi as the President of the Italian Republic. Ciampi, a former Prime Minister and Minister of the Treasury, and before the governor of the Bank of Italy, was elected on the first ballot with an easy margin over the required two-thirds votes. In April 2000, following poor performance by his coalition in regional elections, D'Alema resigned. The succeeding caretaker centre-left government, including most of the same parties, was headed by Giuliano Amato (who previously served as Prime Minister in 1992–93) until the 2001 election. A constitutional referendum in 2001 confirmed a constitutional amendment to introduce early