What different ways can trade barriers be created unintentionally?

One of the ways trade barriers can be created unintentionally is imposing tariff against certain product/s with the intention that such tariff will minimize the importation and create or preserve jobs.  Example of such barriers is when President Obama announced that he would impose a 35 percent tariff on automobiles and light-truck tires imported from China. (The New York Times, September, 12 2012).

This announcement has the propensity to create trade barriers for countries competing for the same product and protecting certain group/industry, such as the Union of American tires and automobile workers, which President Obama wanted to maintain a harmonious relationship with as he win their support when he pushed Congress to overhaul the nation’s health care system. But contrary to this decision was the Tire Industry Association who opposed the tariffs because such tariffs was not certain to preserve American jobs or create new once, protect against cheap foreign lobar, maintained domestic living standard for all, but could instead cause many companies in that industry to relocate their factories to other countries where they can find lower labor cost.  On the political side, it is the responsibility of the government to protect its people by providing national security and sustainable goods or product which they cannot depend solely on foreign companies import but have to enable its citizens to provide.  

Higher safety regulations can be another unintentionally barriers to trade, in which the production of any goods could be more expensive. Some of these safety regulations increase production cost on materials that could have been left out or reduce, but now have to be offered to provide better gas mileage, seat belts and air pollution, just to name a few. With these regulations on foreign companies competing in the same market, they may find it difficult to sell their product for cheaper price as they were hoping for and may have to charge higher price which could lead to them losing their comparative advantage.