By Ariba Shahid and Saad Sayeed KARACHI, June 23 (Reuters) - Pakistan's role in brokering a peace deal in the Iran war has led to widespread diplomatic acclaim that could bring Islamabad some economic benefits, but analysts question whether such gains can help resolve the fault lines in its economy. Prime Minister Shehbaz Sharif and army chief Field Marshal Asim Munir attended talks between Iran and the U.S. in the Swiss town of Buergenstock last weekend, the culmination of Pakistan's months-long role in one of the world's most consequential diplomatic negotiations.