International trade has it's good and bad sides. The opinion about what is good and what is bad about it vary strongly in the political spectrum with some factions having almost symmetrically opposed views.
Many ecologists object to international trade on grounds that transportation of products over long distances is not ecologically sane. Though the mode of transport plays an important role in determining the environmental cost of transporting over long distances. For example sea transport doesn't consume much resources (ie. it is very eco-efficient) and air transport on the other hand releases greenhouse gases straight to the atmosphere where there is no vegetation to tie up the carbon dioxide released and also consumes a lot of fuel.
There is also the opposition based on distress caused to the local economical situation due to the fact that Multinational corporations can move their production and capital around the globe quite quickly and use this possibility to negotiate or extort tax exemptions in countries that fear the loss of employment