Alvear joined the Youth Wing of the Christian Democratic Party at the age of 17 and held various leadership roles during her years of party membership. In 1988, she worked on the
No campaign in the national plebiscite and later joined the presidential campaign of
Patricio Aylwin. Following the return to democracy, she became head of the National Women's Office (ONAM) and later served as the first Minister of the newly created
National Women's Service (SERNAM) between 1991 and 1994. During her tenure, she launched a national equal opportunities plan and promoted legislation against domestic violence. During the administration of President
Eduardo Frei Ruiz-Tagle, Alvear served as Minister of Justice from 1994 until late 1999. In that role, she led a comprehensive reform of Chile's judicial system, including the establishment of a new criminal procedure system, the creation of Family Courts, and the enactment of the Law on Filiação, which eliminated legal distinctions between children born within and outside marriage. In March 2000, President
Ricardo Lagos appointed her Minister of Foreign Affairs. She served until 2004, becoming the first woman to hold that office in Chile. During her tenure, Chile signed free trade agreements with the United States, South Korea, and the European Union, deployed a peace mission to Haiti, and played an active role as a non-permanent member of the
United Nations Security Council. In 2003, Chile voted against a United States–led military intervention in Iraq. Alvear chaired and presided over multiple international forums, including the Rio Group, the Human Security Network, the Organization of American States General Assembly (2003), and APEC Chile 2004. She also presided over the UN Security Council in January 2004. In 2004, she resigned as foreign minister to seek the Christian Democratic Party's presidential nomination for the 2005 elections, withdrawing from the race in May 2005. In the 2005 parliamentary elections, she was elected senator for the 8th Senatorial District (Metropolitan Region East), serving from 2006 to 2014 and obtaining the highest vote share with 582,117 votes (43.81%). In 2006, she was elected president of the Christian Democratic Party, becoming the first woman to lead the party, and served until 2008. She ran for re-election to the Senate in 2013 but was not elected. In April 2018, Alvear resigned from the Christian Democratic Party after fifty years of membership. She subsequently founded the political movement
Comunidad en Movimiento. In May 2018, she was appointed to the National Agreement Table for Comprehensive Development convened by President
Sebastián Piñera. Between 2019 and 2020, she promoted centrist political alliances through agreements with
Progresismo con Progreso. She later joined
Amarillos por Chile in September 2022, remaining in the movement until June 2025. On 23 May 2023, Alvear was elected president of the Honor Tribunal of the
National Professional Football Association (ANFP). ==References==