I wouldn't be against this if they were truly regulating for peace, and not for some other agenda. Some parties are less than friendly towards Bitcoin because of its potential to challenge the world order, and they could use this sitation to their advantage. That's really my only worry.
If the fight is truly against terror and not against Bitcoin itself, then regulations shouldn't be too restrictive and should allow room for Bitcoin's growth. It must acknowledge the fact that Bitcoin isn't inherently evil, and could just as easily be misused as fiat. If they were able to gather data that conclusively determined that Bitcoin has been used for terrorism, then they should have a general idea on how terrorists did it. It should be easy to address from there without taking overly drastic steps.
Really though, international legislation is unlikely. Bitcoin has grown to be a major player in finance, but it's still way too small to merit such attention.