Economics experts fight over numerous of things, it’s the shame of the profession. The fact is that anything can be proven if you use the right econometric techniques, the right time-period and the right data set. So coherent theories are in fact in many ways more important than empirical evidence. Regardless of the dichotomy in economic debate there is at least one thing that would be in the economic bible and that is Free trade.
Free trade just means allowing products in and out of the country without imposing tariffs. The rationale for tariffs is that you want people to buy products that are made inside the country so that money stays in the country and develops the domestic industry. However from the consumer’s point of view, why should he/she care where the product is made? Since if even if the Japanese car industry thrives, they will export their great cars to your country and raise his/her standard of living. Whilst putting tariffs on their cars would either mean the consumer has to either accept a lower quality domestic car or accept to buy the Japanese car anyway at a higher cost, which either way reduces your standard of living because you either have an inferior product or because you have less dispensable income.
The part the Economics profession usually forgets is the politics aspect of tariffs. The reason you might not want to have free trade is if you believe instabilities between two countries will occur. You don’t want Japan to be providing all your cars for you because if they decide they no longer like you and want to go War with you, they can block all their products from coming into your country and helping you. Depending on how good the environment in the country is for setting up businesses, it is likely that either another country will provide the products or domestic industry will emerge, however if the Japanese industry was dominant chances are that your new supplier will not be as proficient, and depending on the product it could have devastating effects on the economy, such as if the product was food, that domestic workers tried to replace without enough expertise and end up selling toxic food.
So tariff’s are rationalized as a bargaining chip between governments, if you believe that relations with two countries are not likely to fall then then free trade is without doubt the route to go. This would probably be the US and Israel or Cyprus and Greece. So China making everything nowadays is not likely to be problematic, unless one believes that they might one day use it against other countries.