Peter Beinert writes: The United States should push for the best nuclear deal with Iran that it possibly can. But it’s now obvious, almost three decades after Reagan signed the INF deal with Gorbachev, that it’s not the technical details that mattered. What mattered was the end of a cold war that had cemented Soviet tyranny and ravaged large chunks of the world. Barack Obama has now begun the process of ending America’s smaller, but still terrible, cold war with Iran. In so doing, he has improved America’s strategic position, brightened the prospects for Iranian freedom and Middle Eastern peace, and brought himself closer to being the kind of transformational, Reaganesque president he always hoped to be.  Ending the Cold War with Iran