It's not the trade that kills economies, it's the monetary system, as well as property rights as recognized by the WTO.
If free trade were in fact harmful, we could expect that the US economy would be even stronger if the states were allowed to enact tarriffs between them. We could also expect that the most successful historical societies were the most culturally and economically isolated. Neither one of these is true.
Henry George asked the question in
Protection or Free Trade:
"One thing or the other must be true—either protection does give better opportunities to labor and raises wages, or it does not. If it does, we who feel that labor has not its rightful opportunities and does not get its fair wages should know it, that we may unite, not merely in sustaining present protection, but in demanding far more. If it does not, then, even if not positively harmful to the working classes, protection is a delusion and a snare, which distracts attention and divides strength, and the quicker it is seen that tariffs cannot raise wages the quicker are those who wish to raise wages likely to find out what can."
Henry George was a progressive labor supporter and political activist near the end of the 19th century. He believed that a primary goal of a democratic government was to increase wages.
I will note that there are roughly 150 million 'jobs' in the US, and roughly 7.5 million 'unemployed' in the US. I recognize these numbers are iffy, and do not account for underemployment or those who have given up. While there are certainly specific cases where jobs have been exported, the cause is not lack of protection, but rather active suppression of domestic employment by our government. Namely, financial returns to land & natural resources are favored over returns to the products of labor, which are in return favored over wages. Note that most income enjoyed by land & resource owners - rent and capital gains - is nearly exempted from taxation; income enjoyed by owners of machinery and capital is taxed at a low ~15% rate; while a man who earns $50,000 a year supplies nearly 40% of his wages to the government, when payroll taxes and state taxes are concerned.
I am absolutely sure that reducing the cost of labor in this country by 40% would increase total employment in this country by more than 5-10%, MORE than eliminating our unemployment, and causing wages to rise.
'Protecting' industries in this country by assigning tarriffs against imports is about as progressive as a national sales tax. It isn't progressive at all. It merely further hides the root problem: we have allowed a relatively small portion of our population appropriate the natural and community-created value of our country. We have allowed the ownership of property to trump the value of labor.