A question I actually have the answer to! Yes, you can upgrade internationally with Miles from Economy to Business on AA. But there is also a Copay invovled unless you booked a full fare coach ticket (Y or B). Here's their upgrade awards page:
http://www.aa.com/i18n/utility/jba-u...servations.jsp
For Ex: My India flight is 40,000 Miles + $350 One way to upgrade from Discount Economy to Business.