Pakistan, May 17 -- As Interior Minister Mohsin Naqvi touched down in Tehran on Saturday, Islamabad continued its quiet shuttle between Washington and Tehran, a scene that would have seemed implausible not too long ago. Pakistan, a country often caricatured in a negative light, is now mediating between two adversaries, and its envoys are running back channels that even reluctant actors are forced to recognise. Uzbekistan's foreign minister is the latest diplomatic voice to appreciate Islamabad's "constructive" role in easing regional tensions. Iran's chief diplomat, Abbas Araghchi, has also acknowledged that Pakistan's mediation "has not failed yet", even though talks remain on a "very difficult course". US President Donald Trump, returni...