In 2002, Cagan was among the founders of United for Peace and Justice, a left-wing coalition of more than 1,300 international and U.S.-based organizations opposed to what they describe as "our government's policy of permanent warfare and empire-building." The organization was founded in the months preceding the 2003 invasion of Iraq. An opponent of military intervention, Cagan is strongly opposed to U.S. military forces staying in Iraq. Her view of Iraqi insurgents fighting U.S.-led coalition forces: "What I do think is legitimate is that people who are being occupied would find a way to work against that occupation. If you call that an insurgency, then so be it." In regards to U.S. relations with Israel, Cagan had described U.S. funds as going "to help maintain the deadly Israeli occupation of Palestinian territories."