Factory jobs are usually a bit different, as a lot of them are just being moved overseas. It's not that it's unprofitable to have the factory in X western country, it's that it is more profitable to have it in Y developing country where wages and regulations are often a lot lower.
It is an interesting problem for some nations / companies. With the USA and their companies China is one of the only viable markets out there to actually show any real growth (I am now excluding the domestic US market and EU). With that said China demands from the companies to set a joint ventures on its soil and produce locally. Without a trade way there is no way to keep the factory jobs in the US and sell in China.
