Why should the United States care about the rehabilitation in Europe, according to Marshall

The US according to Marshall should care about the rehabilitation of the nations of Europe because "there can be no political stability and no assured peace" if the US doesn't assist in the economic health of the world. Also because "our policy is directed not against any country or doctrine but against hunger, poverty, desperation, and chaos". Marshall also stated, "An essential part of any successful action on part of the United States is an understanding on the part of the people of America of the chacter of the problem and the remedies to be applied".