If people wanted to institute new trade barriers I'd probably oppose it on the grounds that not only you hurt some people but the likely aggregate loss (from comparative advantage) would prevent you from compensating the losers.

So let's just wrap up my position with this:

• If you're going to use side payments to argue that a change is fair to most people, the side payments need to be actual, not hypothetical [mathematically: Kaldor-Hicks with actual side payments is probably close to Pareto]
  
• If you're going to advocate a policy change because of an aggregate benefit, you have to use (part of) the aggregate benefit to actually, not hypothetically, compensate those who would otherwise oppose the change because they would be hurt.
  
• On the issue of globalization, probably the thing to do is to liberalize trade while at the same time instituting a fund to help your own workers who will be forced to retrain into abother industry [such a "globalization adjustment fund" has been proposed at the EU level]
  
• I remain unconvinced that with free movement of labour, capital, goods and services it makes sense to talk of separate economies. You then need a common economic policy with explicit redistributive elements to protect people from the whims of capital movements. With fixed labour and capital and moving goods, you can really talk about free trade between distinct economies.