This assertion army be to divide the nation and use the African Americans against the US.
Explanation:
Castro had understood that the plight of the African Americans had been noticed the world over and many even inside the Harlem had understood how they can come out of the segregation era.
He wanted to use this disenfranchised population to make sure that that there is number of people in the US who would stand against the government in time of a conflict.
This was a rather sinister strategy as it would play out inside of the US.
