On the 20th anniversary of the US-led invasion of Iraq, US Senator Tammy Duckworth and NBC's Chief Foreign Correspondent Richard Engel sit down with Ian Bremmer on GZERO World to reflect on the legacy of a war that reshaped the Middle East and continues to reverberate around the world.

Senator Duckworth, a former helicopter pilot who lost both her legs in the Iraq War and now sits on the Senate Armed Services Committee. She emphasizes the importance of honoring the promises made to veterans and the impact it has military readiness. "The cost of going to war isn't just the tanks, the guns, the helicopters, and the ammunition during the period of actual conflict," Duckworth says, "The cost of war goes on for many decades."