Which model acknowledges that a message can be sent and received at the same time?

On what political idea did president truman base the marshall plan? as economic aid increased in europe, the friendship of nations with the united states would increase. as peace throughout the world increased, the threat of another world war would decrease. as prosperity in europe increased, the threat of communism spreading would decrease. as the power of capitalism increased in europe, stalin's power in the soviet union would decrease.