American warplanes bombed a seaside town in Libya early Friday aiming to kill a militant commander linked to attacks on Western tourists. But the mission also highlighted the widening gap between American military operations and diplomatic efforts to bring peace and stability to a tumultuous region. The airstrikes on a training camp in Sabratha, targeting a Tunisian militant associated with planning two major attacks on Western tourists in Tunisia last year, did demonstrate the United States’ growing concern over Libya as a new base for the Islamic State and its willingness to use air power against militant commanders and infrastructure. Yet every counterterrorism victory also underscores the limits of the American approach to the countries where the Islamic State is strongest, […]