When his Vietnam saga "Platoon" appeared, Oliver Stone felt it was a painful reminder of an aggressive mentality he hoped America had left behind. Two decades later, the country has fallen back on old habits, Stone said Sunday at the Cannes Film Festival, where "Platoon" had a 20th anniversary screening in advance of a new DVD edition coming May 30. The Cannes screening of "Platoon" was preceded by footage of Stone's upcoming film "World Trade Center," starring Nicolas Cage in a Sept. 11 drama about two policemen trapped in the rubble of the twin towers after the terrorist attacks. AP reports.