Like two hostile prisoners on the run and shackled to each other by fate, Iran and the United States continue their mutual loathing and periodic conflict. The inevitability of talking and even cooperating, however, also looms over both in a region neither can shape unilaterally. Washington and Tehran’s shared distaste for a wider military conflict and the gradual demise of the Iran nuclear agreement are again focusing attention on the path to any renewed U.S.-Iranian diplomacy.