It’s slow going for NAFTA negotiations. Not just for the big ideas that Mexico, Canada and the U.S. want to include, but also for the line-by-line edits.

That’s where the 25-year-old agreement stands right now. The second round of renegotiation talks wrapped up here in Mexico City this week.

And to get an understanding of what’s happening behind closed doors, we turn to Antonio Ortiz Mena. He’s a senior adviser at the consulting firm Albright Stonebridge group.

And he was a member of Mexico's original NAFTA negotiation office in the 1990s.