Under Secretary for Political Affairs Wendy Sherman, Secretary of Energy Ernest Moniz and Secretary of State John Kerry in Lausanne, Switzerland, in March. (Brendan Smialowski?Associated Press)

Iran sanctions experts Eric Edelman and Ray Takeyh explain:

In as little as a few months, Iran will for all intents and purposes no longer be a sanctioned country. Although elaborate and protracted procedures are in place for the re-imposition of the U.N. Security Council sanctions resolutions, the economic sanctions imposed by the European Union and the United States — always the most essential ones — will be rolled back quickly and will not be easily reconstituted.

To repeat: What was supposed to be a phased withdrawal of the sanctions so as to see if Iran is allowing access to inspectors and keeping to other obligations is now transformed into a rollback of all sanctions as early as the end of this year. By 2016, sanctions will be largely gone and the only recourse if Iran begins, as it has in the past, stiff-arming inspectors (who can be stalled for as many as 24 days) is a snapback provision that takes 50 days, grandfathers old deals and then lets Iran out of any and all existing obligations if sanctions are reapplied. With the concessions Iran obtained this year, it can now resume enrichment after eight years

One can easily imagine that Iran will take its $100 billion in sanctions relief and immediately begin throwing up roadblocks to inspections, backtracking on commitments and exceeding the limits on its program. And, of course, it is allowed to proceed with advanced R &D (which have the effect of shortening breakout) and progressing on its ICBM program, the only purpose of which is delivery of a nuclear weapon. Recall as well that Fordow is not dismantled and Iran keeps 6,000 centrifuges spinning. This is only one reason the deal must be thwarted before it begins.

Put differently, it is very easy for Iran to get sanctions pulled back and very hard for the West to reimpose them. Bloomberg reports, “More concerns arise from the ‘road map’ that the International Atomic Energy Agency released Tuesday, on how it will resolve longstanding questions about the history of Iran’s efforts to build a nuclear weapon. First, the description of how it plans to do so is dangerously vague. Equally important: Until May, the U.S. position was that Iran had to come clean about that history before there would be any sanctions relief. Now that issue has been shunted aside in terms of lifting sanctions.”

This is not to say a new president could not pull the plug. He or she must do so, but the question is how. This is not a time for amateurs or chest-beating.  A new president would need to do a lot of preparation and legwork before pulling the plug. The Obama team has booby-trapped this deal, giving Iran huge advantages and putting the United States at risk. Ripping it up with no thought to how it is done will wind up needlessly harming the United States while allowing Iran to keep all the benefits of the deal. Beginning in the transition, the new president is going to have to navigate the treacherous path President Obama has put us on.

The new president would want to assess whether Iran quite frankly already has a bomb. He or she would need to get allies, if possible, to recognize Iran’s violation and obtain cooperation in re-establishing sanctions; prepare to enforce and upgrade sanctions; consult with allies to develop, a military option; and prepare allies whose businesses have rushed into Iran to curtail any new activity in accord with reimposed sanctions. Do we have an adequate war plan if Iran reacts militarily? Will Israel be prepared?

Then there are the E.U. and other allies. They will all be doing business in Iran and in order to garner their cooperation and have any chance to pursue any non-military option, we will need to try getting them on board (preferably by using the snapback sanctions in the deal.)

When the new president arrives on Day One, the Pentagon, intelligence community and NSC will be stocked with Obama left-overs and will need to be managed so as not to undermine actions. It is well and good for someone who has never been responsible for national security to say he needs no information or guidance and can instantaneously reverse course; the reality is a sober and careful plan to undo Obama’s damage would be required. It is the difference between taking a sledge-hammer to a ticking time bomb and getting a bomb squad to dismantle it with skillfully.

Iran is not North Korea. When President George W. Bush pulled out of that framework deal (also crafted under Wendy Sherman) our adversary was not engaged in proxy wars, did not have the capacity to strike an ally like Israel, was not economically sophisticated and did not threaten to topple its neighbors. It did not have a sophisticated and viable missile program underway. Despite that decision, North Korea still got the bomb — something the United States has said we could not live with in the case of Iran.

In sum, the deal would radically and quickly shift leverage to Iran, would infuse the Middle East with Iranian weapons and money and thereby severely diminish the non-military options for thwarting Iran. Iran could well try to threaten Israel with conventional war or use its terrorist surrogates to threaten U.S. interests. As soon as he or she is elected, a new president therefore would not only need to plot out how to restart the sanctions; he or she would need to come up with a credible military backstop, depending on how far Iran had progressed.

For all these reasons, it is essential to stop the deal before these complicating factors are set in motion. And it’s why — in a GOP field where virtually all candidates are committed to ending the deal — the voters should choose the one who knows how to accomplish that. It will take much more skill to safely extract us from this horrific deal than it has getting us into it.