According to GlobalSecurity:
With the formation of the elite Qods (Jerusalem) Force of the IRGC, Ahmadinejad became one of its senior commanders. He directed assassinations in the Middle East and Europe, including the assassination of Iranian Kurdish leader Abdorrahman Qassemlou, who was shot dead by senior officers of the Revolutionary Guards in a Vienna flat in July 1989. Ahmadinejad was a key planner of the attack. He was reported to have been involved in planning an attempt on the life of Salman Rushdie.
To make matters worse:
Ahmadinejad is a member of the central council of the hard-line Islamic Revolution Devotees' Society (Jamiyat-i Isargaran-i Inqilab-i Islami). The Devotees publicly endorsed another candidate -- Mohammad Bagher Ghalibaf -- in the 17 June 2005 first round of the presidential election. Both the Developers and the Devotees represent the younger generation of Iranians with a background in the Revolutionary Guards and the 1980-88 Iran-Iraq War. Ahmadinejad represents the rise of this new generation.
Nuclear weapons in the hands of such people is a recipe for global disaster.