Nowadays we usually hear of Donald Trump's wall. In fact during his campaigning Trump promised to his voters that he he would have built a wall to mark the American border. I think that the wall has both strenghts and weaknesses. In fact it could be positive because it can reduce the illegal immigration, the drug trafficking and the money laundering but it can be negative and dangerous because it doesen't allow the cultural exchange anymore between the countries. Actually the building of the wall is just like a double-edged sword!