He even endorsed the idea of launching military strikes against Iran, accusing Tehran of supporting anti-US forces in Iraq and attacking American soldiers deployed in the Arab country.
"I think we've got to be prepared to take aggressive military action against the Iranians to stop them from killing Americans in Iraq," Lieberman said in an interview with Bob Schieffer of CBS in 2009.
The US senator also criticized the Obama administration’s policies towards Iran's nuclear energy program, saying that the US must lead a global coalition to attack Iran.
In September 2012, Lieberman accused Iran of launching cyber attacks on US banks because of what he called “retaliation for US economic sanctions on the country.”
US Senator Joe Lieberman, who is known for his strong anti-Iran views and ardent support of the Zionist regime of Israel, is leaving office after 24 years.
The 70-year-old senator had announced in January 2011 that he would “not be a candidate for re-election to a fifth term in the US Senate in 2012.”
Lieberman was elected to the Connecticut State Senate in 1970 where he served for ten years. He also served as Connecticut's Attorney General from 1983 to 1988.
After gaining popularity for his consumer and environmental advocacy, Lieberman went on to win his first election to the US Senate in 1988, winning the seat twice more in 1994 and 2000.
The first Orthodox Jew to serve in the Senate, Lieberman was the Democratic candidate for Vice President alongside Al Gore and the first Jew named to an American national ticket.
Lieberman endorsed the Republican nominee John McCain in the 2008 United States Presidential Election, a move which enraged his Democratic Party members.
In his speech during the second session of the Republican convention in 2008, Lieberman compared the then Democratic senator Barack Obama and John McCain, saying that in the Senate, Obama did not reach across party lines to get anything significant done, nor was he willing to take on powerful interest groups in the Democratic Party.
Lieberman was also among the most important and outspoken supporters of the Bush administration's Iraq war policies.