The short version: NAFTA is a scam for enrichment of transnational corporations, and the "world economy / can't be isolationists" thing is one of several bogus arguments for it.
The longer version:
Did you now that under NAFTA corporations have the power to sue entire nations for "unrealized profits", that there's such a thing as the NAFTA court which is de facto more powerful then the International Criminal Court? That's how Mexico got fined 17.5 Million to be paid to the corporation that wasn't allowed by Mexico to build a chemical waste dump on top of an aquafer somewhere in Mexico. All that Mexico did was refer to its environmental laws - problem is that environmental laws, much like labor rights and Unions, are in the context of Globalization considered to be "trade barriers". Obviously barriers need to be removed.
NAFTA and similar agreements (FTAA, GATT) along with the rules and regulations that go with it, are created behind closed doors, entirely undemocratically. NAFTA court is more powerful then the ICC in that the ICC can (apparently) not be called upon as a higher authority to question the legitimacy of the NAFTA court.
google: NAFTA Mexico Metalclad.
The least you'll find is that i didn't just make up this story.
NAFTA's chapter 11
"...gives corporations rights to sue governments in special tribunals, for unlimited compensation for profits lost due to normal governments activities."
"...there have been cases, like "Metalclad".
An American company called "Metalclad" went down to Mexico to build a toxic waste dump on an aquafer; the local supply of water. The government said "no, this goes against our environmental laws".
The people are getting poisoned from the water - what corporation has a right to poison our water? The government passed a law that said "no, you can't operate this thing".
They said "that's to bad, we have rights as a corporation that outweigh your human rights". They sued them for 17.5 million dollars saying it was a barrier to fee trade.
This US corporation takes the Mexican government to a NAFTA court, sues under this chapter eleven, and the ruling is - the Mexican government has to pay millions of dollars in "penalties", for "lost profits" of this corporation."
from the documentary "Trading Freedom" (Indymedia)
http://www.indymedia.org.uk/en/2004/01/284511.htmlalso documented at
Berkeley University
http://are.berkeley.edu/courses/EEP131/classpresentations/Metalclad.pdf (PDF)
(turns out the amount in penalties to be payed by the Mexican government was reduced, but "...the judge agreed with the NAFTA panel on the merits that the actions of the Governor constituted expropriation".
New York Law Journal
http://www.clm.com/pubs/pub-990359_1.htmlStop FTAA
http://www.stopftaa.org/article.php?id=37"NAFTA Chapter 11 Investor-to-State Cases: Bankrupting Democracy"
http://are.berkeley.edu/courses/EEP131/Nafta_Chapter11.pdf (PDF)
There are plenty more examples where that came from.
Can you name even one concrete example where NAFTA did any good for 'ordinary people'?