The attack targeted the Iranian-backed Shia militia in Iraq, marking a major escalation in U.S.-Iran tensions.
2020 is the new 2003.
The senator from Vermont also attacked his Democratic presidential rival for his positions on issues like trade, health care and the 2005 bankruptcy bill.
The post-9/11 generation is a core of the Vermont senator's White House campaign coalition.
"This is an example of why years in Washington is not always the same thing as judgment," the Democratic presidential contender said of his rival.
The Iraq War was famously based on a false claim.
The former U.S. ambassador's wife at the time, Valerie Plame, was outed as a CIA agent shortly after he spoke out on the Iraq invasion.
Nicholas Slatten played a part in a 2007 massacre of Iraqi civilians, including children.
The freshman senator from Arizona used her maiden speech to tell the story of an Iraq War veteran who died by suicide.
David Bellavia, who is credited with saving the lives of his entire squad, will receive the nation's highest military decoration.