Barbara Slavin writes: Robert Einhorn, a former senior U.S. official who is well regarded by the Obama administration and retains close ties to its top nuclear negotiator, has proposed parameters for a long-term nuclear agreement with Iran that would allow it to continue enriching uranium at low levels and would ask Congress to pre-authorize military action in response to Iran violating the accord.

Einhorn’s proposal — unveiled Monday at the Brookings Institution where he is currently a senior fellow — seeks to marry Iran’s current limited need for nuclear fuel to the scope of its nuclear infrastructure, and provide confidence that Iran will not develop nuclear weapons.

In publishing his ideas, Einhorn — who left the Obama administration less than a year ago and retains close ties to chief U.S. negotiator Wendy Sherman and other administration officials — is illustrating that the fate of a long-term nuclear agreement with Iran rests not just on the negotiators meeting in Vienna, but on how political elites in the United States and Iran approach the compromises that will be realistically required to reach an accord. U.S. officials have compared the process of broadening the current six-month interim agreement to solving a Rubik’s Cube, in which changes in any one provision affect all others. [Continue reading…]