When antagonist countries are at odds on everything else, swapping prisoners can be a low-cost way of easing tension while scoring small successes for the respective leaders. Iran and the United States managed one such win-win prisoner swap in early December. Arrangements are largely worked out for another, but will require both sides to take yes for an answer.
On Dec. 7, Princeton doctoral student Xiyue Wang was released from his 3-year-long imprisonment in Iran in exchange for the US release of Iranian stem-cell scientist Masoud Soleimani. The latter had been arrested for a failing to obtain the required licenses to export human growth products for medical research, a minor violation of sanctions regulations.