We probably have a pretty fair list of the individuals in Iraq because of almost 3 years of weapons monitoring but to indentify these individuals in Pakistan or Iran without the cooperation of their respective governments may be difficult.
Just get the grad student lists for American and European University Science Departments for the past 30 years, and cross check them with lists of foreigners who have been naturalized or remain in the country as resident aliens. Its not like Nuke Science is a common course of study in Tehran U.