If you ban free trade, you cannot expect people to buy from you. A country must exist by exporting either goods and or services. A massive company like Walmart might seem all powerful but it must be remembered it needs the vast market place of the US to survive. If customers don't like it's business practices, for example the low wages and conditions they must make Walmart know about that by voting with their feet. I know this can be very effective because some years ago, it was discovered that M and S, a very high profile store here and internationally, was receiving garments, made in Asia, in factories with appallingly poor and dangerous conditions and employing children in very unsafe environments. The press made a big issue of it and the public got behind them. M and S were held accountable for the way these Asian workers were being treated and was able to put sufficient pressure on their suppliers to conform with UK safety standards and the employment of children acts. Now they regularly inspect these factories. Never underestimate the power of the consumer in all this. Ethical businesses sell!!!
If Wal-Mart needs the "vast market place of the US to survive", how do you explain the stores they have opened all over the world ?
http://corporate.walmart.com/our-story/our-business/locations/