President Trump speaks at the 72nd U.N. General Assembly at U.N. headquarters in New York on Sept. 19, 2017, in New York City. (Spencer Platt/Getty Images)

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President Trump hasn't been shy expressing his distaste for the Iran nuclear deal negotiated under his predecessor. He has called the 2015 agreement disastrous, horrible, and one-sided, and he has vowed to get rid of it or renegotiate the terms. Trump has already given his approval twice to preserve the agreement, albeit grudginglyThe Joint Comprehensive Plan of Action (JCPOA) — which took 13 years to negotiate but was accelerated in the last two years of the Obama administration — restricts Iran's nuclear program and lifts some sanctions.

Trump plans to make a speech today at the White House announcing that the U.S. will not withdraw from the agreement. Instead, Trump is expected to send the matter to Congress, which will have to decide whether to snap back into effect the U.S. sanctions on Iran that were lifted under the deal.

Despite Trump's disdain for what he considers a failed policy and the “worst deal ever,” many top officials in his administration support staying in. Defense Secretary Jim Mattis considers the deal vital to the national security interest of the United States.

So why does Trump hate the deal so much? Here are some reasons:

1. Iran got money from it.

When Trump was running for office, he often brought up this line: “We give them $150 billion, we get nothing.” He referenced it in a New York Times interview and on stage during the second presidential debate. Trump's chief complaint was that the U.S. forked over a massive sum of money in a “one-sided transaction.” But that's not accurate.

The money belonged to Iran, mostly from limited, legal oil sales. It was frozen in banks around the world because of sanctions on its nuclear program. The release of the money was part of the negotiated deal.

And Iran got much less. The total unfrozen accounts yielded about $100 billion. The Treasury Department estimated that Iran got roughly half that — and some say it got much less — after debts were paid. Other assets not tied to its nuclear program are still frozen.

2. The deal does not prevent Iran from testing ballistic missiles. 

Trump got fired up in September, tweeting that Iran had tested a ballistic missile. “Iran just test-fired a Ballistic Missile capable of reaching Israel,” he wrote. “They are also working with North Korea. Not much of an agreement we have!” In fact, video footage released by Iran's state media showed a failed missile launch in January — not a live launch.

Iran has successfully tested a new ballistic missile with a range of 2,000 km, state media said. (Reuters)

The nuclear deal was limited to the nuclear program. The rationale was that it would be better to confront Iran over other contentious issues if it didn't have enough fissile material to build a nuclear bomb. Those issues were always intended to be addressed separately. Iran, without a nuclear bomb, had more sanctions on it than North Korea, which possesses several.

3. The inspectors have limited monitoring powers. 

Trump has complained that the International Atomic Energy Agency, the U.N. organization responsible for inspecting Iran's facilities,  does not have sufficient monitoring powers over the nuclear facilities. He and other critics say the inspectors have no access to closed military sites where any suspect work might be done in secrecy.

Actually, the agreement does make some provision for inspecting military sites. But in requesting access, the IAEA must show Iran the basis for its concern. Iranian officials have repeatedly said the military sites are off-limits to the IAEA.

4. Some parts of the agreement are not permanent.

This was the part of the deal that took the longest to negotiate. Various “sunset provisions” stipulate expiration dates for restrictions imposed on Iran’s nuclear program. Critics say that when they expire, Iran will be freed to build or acquire nuclear weapons.

Some of the limits, such as those on centrifuges and on research and development of more-advanced ones, end in 2025. Others last longer. Some restrictions that make it hard for Iran for build nuclear weapons remain in place indefinitely. Iran did agree to never build nuclear weapons.

5. Iran has not ‘lived up to the spirit' of the agreement

Last week, in a meeting of military leaders, Trump said that Iran has not “lived up to the spirit of their agreement.”

In accusing Iran of falling down on the deal's expectations, administration officials cite a phrase in the preamble, in which the signatories “anticipate that full implementation of this JCPOA will positively contribute to regional and international peace and security.” Trump claims Iran is defaulting on its promises by supporting Bashar al-Assad in Syria, supporting militias in other countries, and developing ballistic missiles for what Iran says is self-defense.

No one disagrees that Iran's activities are a destabilizing influence in the region. But the six world powers that negotiated the deal with Iran said at the time it was solely about Iran's nuclear program. A primary goal was to ensure that regional tensions did not lead to a nuclear arms race.

Read more:

 

Iran nuclear deal: What you need to know

Trump’s generals thwart him on the Iran deal

Europe helped draft the Iran nuclear deal. Now leaders are trying to save it.