The article discusses how trade tensions between the U.S. and other countries increase uncertainty about future trade policies. Using a model that looks at different types of companies, researchers found that when expectations rise about tariffs going up, firms are less likely to enter foreign markets. The study combines different ideas to show that this uncertainty affects the economy significantly. The potential effects of a full-blown trade war are even bigger than just uncertainty about trade policies, with global trade predicted to decrease significantly in such a scenario. In short, uncertainty about trade policies can hurt the economy quite a bit, but an actual trade war would have an even more substantial negative impact.