The source of main problems (including rearmament, hunger and wars) are systemic problems in Marxian sense. That is, while humanity as a species have the technical and material conditions of solving most of the problems (hunger, most of diseases) and this is called "productive forces" (i.e. the social production in the global scale) in Marxian terminology, the "production relations" (i.e. the private ownership of the means of the production) impeding these productive forces. So, we have the anarchy in the global market. We have tensions between big groups and states. The capitalism, especially in its maturity phase called imperialism (articulated scientifically and clarity by Lenin), is not efficient enough anymore. Don't talk about USSR and China or Cuba, since in reality they were and are all state capitalism. Go back and read Marx, Engles and Lenin, not cheap talk by academic so-called Marxists or radical chic gauche buddies.