Brad,
Even if only 3% of the value of US GDP comes from the third world, doesn't this three percent take on accumulative effects over time? That same 3% of US GDP is in some cases a staggeringly large percent of a third world country's GDP.
More importantly, much of the value transfer from the periphery to the core is in the form of essential raw materials and agricultural output that are (1) cheaper as imports (2) not widely available or simply not available at all. If the US had to meet its current industrial output by only using raw materials (oil, agricultural products, minerals, timber etc.) available within the geographic boundaries of the US the entire "American" way of life would have to be radically altered.
Costa Rican coffee, cotton from El Salvador, banana's from Honduras, and beef from Nicaruaga might not add up to much of the US GDP but they are part of the consumption norm in the US. The agricultural export economies of Latin America deny peasants access to sufficient parcels of land, impose brutal work conditions in plantation production and incur enormous ecological destruction as rain forest is turned into pasture and water supplies are poisoned by agrochemicals. The driving logic behind this social degradation is U.S. imperialism. At various times people like Arbenz, Castro and the Sandinistas have tried to alter this logic and have been blockaded, invaded and assasinated for their efforts. Imperialism isn't just about percent GDP, but involves essential use-values as well.
P.S. The base line for comparing Cuba's political and economic development isn't Berkeley California. Given the role of US imperialism and Cuba's position in the world-economy as an agricultural periphery a more realistic comparision is between Cuba and Haiti. Warts and all Cuba is a much better place to live than Haiti.
Sean Noonan seanno at ksu.edu