Tehran — Iran has agreed to abandon its nuclear-weapons program in a historic diplomatic achievement certain to dominate tonight’s foreign-policy presidential debate, and dramatically reshape the electoral landscape. “This is an extraordinary breakthrough,” said Deputy Undersecretary of State Jonathan Ebert Jr., lead negotiator for the U.S. “It’s a tribute to the hard work of our diplomatic team and President Obama’s visionary leadership.” According to Ebert, the momentous deal was struck late Sunday night after President Obama called Mahmoud Ahmadinejad and personally apologized for a Madonna video the Iranian leader found offensive. “Ahmadinejad had originally insisted we apologize for Beyonce’s ‘Single...