It would absolutely start a trade war, that America would lose very quickly. The incorrect assumption here is that America has more to gain than lose from doing that, when such couldn't be further from the truth. America is temporarily riding on a fake consumer driven economy supported by the cheapest debt in world history and cheap imports from other countries like China; emphasis on temporary. Our ability to rapidly scale up domestic manufacturing is non-existent, so in the midst of a serious trade war, nearly every single thing Americans buy would skyrocket in price and decimate the already tapped-out consumer, leading to millions of laid-off service sector workers.

This is going to happen anyway, as China and others can increasingly afford their own cheap goods and don't need to export them to us, and the days of cheap debt are coming to an end very soon. It would just accelerate the erosion of what's left of America's economic fantasy. And none of this even touches on the dumping of US Govt. junk paper by a country like China, which would collapse the economy instantly into either an Argentina / Venezuela style inflation nightmare (as the Fed has to print ever larger sums to keep the government solvent), or a Greece slash & burn scenario.