To non-Naderites, it might seem benign. Countries choosing to sign such a treaty would agree to admit foreign investment, with limited exceptions, and give foreigners legal status equal to that accorded to domestic investors. If allowed to flow freely, capital would often go to where it could do the most good, relieving the misery of people who toil for a pittance in places like India or Bangladesh. The MAI gives foreigners legal status equal to domestic investors. Countries choosing to sign such a treaty agree to admit foreign investment.
Direct investment creates jobs.
Rich countries have more capital to invest than the poor countries. So the rich countries will send their capital to the poor countries. This capital will create wealth and make the poor nations wealthier. But while the international left weeps publicly about the wretched of the earth, it isn't much inclined toward practical ways of helping them. Indeed, rather the contrary.