Rumsfeld, widely considered the architect of the US invasion of Iraq in 2003, died at the age of 88 in Taos, New Mexico, his family announced on Wednesday. Rumsfeld served as US Defence Secretary twice, under President Gerald Ford in the 1970s and in the George W. Bush administration from 2001-2006.
"With eyes open he allowed himself to be manipulated into attacking a country [Iraq] that in no way threatened the United States," Giraldi said. "The consequences of that false step are still being experienced to this day, with a continued presence of US forces in Iraq as well as in neighboring Syria against the wishes and stability of both countries."
Both military presences, Giraldi added, remained "part and parcel of an ongoing war crime by the United States."
Rumsfeld was also known for witty - yet controversial - quotes including the now famous (or infamous) "there are known unknowns" about intelligence matters. He also once rhetorically posed the question: "Are we [the United States] creating more terrorists than we're killing?"
He also came under fire over the treatment of prisoners at Guantanamo Bay and enhanced interrogation techniques that many rights groups believe amounted to torture.