Quid Pro Quo?
Two thirds of people detained during post-election unrest in Tehran last month have already been freed and another 100 will soon be released, Iran's police chief was quoted as saying on Wednesday."One hundred more will be released in the next two days," state broadcaster IRIB quoted Esmail Ahmadi-Moghaddam as saying in the northwestern city of Qazvin.
U.S. forces on Thursday released five Iranian officials who were detained in January 2007 in northern Iraq on suspicion of aiding Shiite Iraqi militants, Iranian and Iraqi officials said.
Don't want to speculate too much on this, but it's fair to say that both these matters would have been mutually understood roadblocks to future negotiations between Iran and the United States. Obviously, Iran disputed the arrest of its officials. As for the US, the prolonged and indefinite incarceration of Iranian demonstrators would certainly have made diplomatic overtures tricky for President Obama.
Both gestures make matters a little easier.
(h/t Uskowi)