I am Vietnamese, Why such pictures?

I know many vietnamese people left back in the country lives in poverty. But life over there was like that, and what made it worst was the U.S. Troops coming over there giving them empty promises, and when the GI's realized that they had very little chance of winning that war? What did they do? They dropped everything and just left our country in vain. Who knows,. maybe communist wasn't so bad and Vietnam could've lived up like China today. Well, I haven't much to say because I'm just a 17 year old who has never been to Vietnam ( I wasn't even born there), all I have to say about these pictures are that they make me feel every selfish for living here in the US. The troops leaving Vietnam back then is the cause for the poverty that Vietnam is in right now. These pictures. . . god. . it makes me feel so sad. . deeply.