Editor's Note: The United States and Iran, two bitterly opposed countries, made a rare prisoner swap in Switzerland on Saturday, Teheran freeing Chinese-American researcher Wang Xiyue who had been held since 2016, in exchange for the release of Iranian scientist Masoud Soleimani who had been held by the US for more than a year. Beijing News comments:

This is the latest conciliatory move between the two arch foes since the US unilaterally withdrew from the Iran nuclear agreement on May 9 last year, especially after its aircraft carrier strike groups entered the Persian Gulf in May and November in a show of force.

Compared with the Soleimani case, the Wang case has attracted more attention. This is not only because of Wang's Chinese-American identity, but also because the two cases have a significant difference in transmission power. Wang is a doctoral student in the department of history at Princeton University who went to Iran in 2016 for his doctoral dissertation related to Iran, and was arrested while leaving Iran in August of the same year on the charge of "attempting to collect highly classified articles for British and US academic institutions". In 2017, Wang was sentenced to 10 years in prison for espionage. Soleimani is an Iranian stem-cell researcher who was arrested in Chicago last October after he made a trip to the US to complete his research on treating stroke patients. The US accused Soleimani of delivering a shipment of recombinant protein, worth $8,000, to Iran in 2016 through two students who returned from the US, which it said violated US trade sanctions. Soleimani was in custody for more than a year without being indicted.

The return of detained US citizens abroad has been one of US President Donald Trump's diplomatic appeals for years, and that the exchange came in the run-up to the US presidential elections is proof that Trump is seeking to fulfill his commitments. For Iran, the prisoner swap can temporarily ease relations with the US allowing it to focus on domestic affairs and laying out channels for its oil exports.

But it is early to say the latest prisoner swap marks the warming of US-Iran relations, given that the larger-scale prisoner swap in 2016 did not improve bilateral ties, but made it more difficult to ease bilateral tensions.