> Now, you can argue that you won't go completely closed but I think you will lose out in proportion to how much you close things, specially if you do it to the point that other countries find themselves needing to retaliate with their own trade barriers and alternative trade treaties...
I agree with you the most here, and think it's true that unless a trade policy of that nature is implemented very carefully it could easily cause more harm than good. On the other hand, I think concerns about a complete walling off of collaboration/trade, or US manufacturers suddenly becoming unaware of international markets are overstated.
Manufacturers who have stayed alive already compete aggressively on price, which for them is more about materials management, relationships with suppliers (NXP, Samtec, Maxim, whoever), and process optimization. Component cost varies pretty dramatically by region, and how effectively a US based shop can navigate that is a big determining factor in how competitive they are with China/Mexico/etc.
From that perspective, most of the burden of something like a border adjustment tax is primarily on their customers, especially if they only do mid or low volume / high complexity runs (think medical/telecom/some consumer stuff). High volume / low complexity isn't something most US shops are geared for these days [1], so manufacturing will likely remain overseas and see a price increase in line with whatever policy change occurs. That probably won't hold true for high volume / high complexity (smartphones, etc) where cost of total assembly is higher. That seems to align with all the chatter about Foxconn, Samsung, Sharp, Toyota, etc. investing in US operations. [2][3]
The risks you mention are absolutely real, and my biggest hope at this stage is that any proposed changes are drafted and discussed openly, and given ample time for public review and comment.
1. http://www.assemblymag.com/articles/83764-managing-high-mix-...
2. https://www.macrumors.com/2017/02/08/sharp-lead-on-7-billion...
3. https://www.nytimes.com/2017/02/12/business/trump-asia-aliba...