You can't really compare Iraq to Germany or Japan. Germany and Japan are both racially and culturally homogenous (or nearly so). Iraq is a bunch of separate clans and was artificially stuck together. Japan and Germany were never in any danger of a civil war after the war.
Tariffs do help prop up the wages of the factory workers, but they do so at the expense of literally everyone else in the country. Japanese cars were a godsend to the American consumer. Cheaper and more reliable, they certainly did NOT make corporate America very happy and they did not make our factory workers happy, either. But we got good cars for our money, and eventually the superior imports forced the US automakers to improve. This happened in other industries as well, and now we still produce a massive amount of stuff with a huge industrial base, but we do so much more efficiently. That means lower costs for all consumers.
I do worry about labor, though. The problem is that free trade requires (a) free movement of capital, (b) free movement of goods, and (c) free movement of labor. While we have 'a' and 'b', we most certainly do not have 'c'. This is a major imbalance that is not addressed sufficiently in NAFTA (and I suspect the PTT). I think that labor needs more emphasis in these trade agreements.