Forty-six years ago, on April 30, 1975, the tanks of the Northern Vietnamese army rolled into Saigon (now known as Ho Chi Min City), the capital of South Vietnam. A soldier jumped from the tank and ran into the presidential palace to raise the Viet Cong flag on the balcony of the fourth floor. The two-decades-long Vietnam war between the capitalist South and communist North Vietnam was over. Saigon has fallen to the communists. Duc Nguyen was only 10 years old when this happened. In the space of several years, he would see the freedom-loving city that he once loved transform into a place where he needed to flee for his life. Nguyen noted that the communist his world upside down. “It is a world turning upside down,” Nguyen said. “They would kick you out of the house if you have a house that they like,” he added. “They would …