Social justice means to be charitable to the poor and needy.
There's a difference between those who are "in need" because of circumstances beyond their control and those "in want" due to consequences of choice and free will.
For example:
In America, we have the psychically disabled. They did not choose their circumstances, and we should care for them. Their poverty is beyond their control.
We also have lazy SOB's who think they should get a free handout because getting up out of bed is too hard. Their poverty is chosen, and we owe them nothing. Let them get their own jobs. "Thou shall not covet they neighbors goods", nor shall one man be used as another mans slave.
That does not, however, explain the desire to relieve nations of debt and control trade. These are not governments that are going to use excess funds for welfare programs by any stretch of the imagination, and it is their own policies that allow and even encourage the exploitation of their labor force.