As Washington tightened its economic grip on Tehran through sweeping new sanctions, Pakistan stepped quietly into the space between confrontation and catastrophe, dispatching its most senior military and civilian officials to hold direct talks with Iranian leadership. The effort reflects an older instinct in diplomacy — that when great powers move toward collision, smaller nations with relationships on both sides sometimes carry the only available thread of de-escalation. Whether that thread holds against the weight of American financial pressure and Iranian defiance is the question now shapin