After Ahmadinejad's letter to Bush (PDF) was dismissed by the whitehouse officials and was labeled as provocative and accusing, Dr. Rohani sent a second letter (Iran's Nuclear Program: The Way Out), not to Bush, but to "the international community", whose representative is in the US !.
Ahmadinejad's letter: As I have concluded before, Ahmadinejad has three ball but no experience, and that is why he wrote such letter. He is in no place to write about human rights and Abu Gharib if the prisoners in his country of presidency are tortured. Such letter should have been written by the pope (and it wouldn't have been labeled as provocative, but a brave move)
Dr. Rohani's article in TIME: Dr. Rohani, on the other hand has been very smart on touching the bases for the concerns propagated in the mainstream media about Iran. He starts his article with:
"A nuclear weaponized Iran destabilizes the region, prompts a regional arms race, and wastes the scarce resources in the region."
implying that the option of having a nuclear bomb has already been discussed, but rejected by the Iranian officials.