I find it sad that the word imperialism has only been used once in this thread despite the fact that that one word essentially answers the OP's question.
The Third World is "locked" in a position of poverty because the first and second world coercively remove the capital that they generate through imperialism.
"The Communists disdain to conceal their views and aims. They openly declare that their ends can be attained only by the forcible overthrow of all existing social conditions. Let the ruling classes tremble at a Communistic revolution. The proletarians have nothing to lose but their chains. They have a world to win.
Workers of the World Unite!" -Karl Marx
"The dictatorship of the proletariat, i.e., the organization of the vanguard of the oppressed as the ruling class for the purpose of suppressing the oppressors, cannot result merely in an expansion of democracy. Simultaneously with an immense expansion of democracy, which for the first time becomes democracy for the poor, democracy for the people, and not democracy for the money-bags, the dictatorship of the proletariat imposes a series of restrictions on the freedom of the oppressors, the exploiters, the capitalists. " -Vladimir Lenin
"The People's democratic dictatorship needs the leadership of the working class. For it is only the working class that is most far-sighted, most selfless and most thoroughly revolutionary. The entire history of revolution proves that without the leadership of the working class revolution fails and that with the leadership of the working class revolution triumphs." -Mao Zedong