The State Department, as required by law, informed Congress that Iran is in compliance with the nuclear deal negotiated by President Obama and the five European powers.  The State Department must update Congress regarding Iran's compliance with the agreement every 90 days.

But in parallel with the department's certification of compliance, there is a full-scale review of the deal being undertaken by the National Security Council, which is looking into the question of whether the agreement is compatible with U.S. national security.

The Hill:

"Notwithstanding, Iran remains a leading state sponsor of terror through many platforms and methods," Secretary of State Rex Tillerson wrote in a letter to House Speaker Paul Ryan.  

Tillerson said the National Security Council will lead a review of the deal "that will evaluate whether suspension of sanctions related to Iran pursuant to the JCPOA is vital to the national security interests of the United States."

Under the agreement, the U.S. and other nations agreed to lift some sanctions on Iran in exchange for the country curbing its nuclear program. 

Iran has continued to fund Hezb'allah to the tune of about $250 million a year.  That money goes to paying and arming the militia, who continue to be responsible for some of the worst atrocities in Syria.  Iran is also engaged in a terror war in Yemen, supporting the minority Houthi tribe, who are fighting the government for control.

Iran, through Hezb'allah, also has a close relationship with South American and Mexican drug cartels.  It's hard to see how lifting sanctions on Iran serves American national security.

But the president may still decide to keep the agreement in place.  That's because withdrawing from the deal may cause more problems with our regional and international allies (the exception being Israel) than sticking with it.  Trump faces a similar dilemma with the Paris climate accord.  Although he promised during the campaign to withdraw, he and his aides are finding it more complicated than they thought during the presidential race.

Trump may decide to withdraw from both deals anyway, after making an attempt to renegotiate some aspects of the agreements.  That effort is not likely to achieve any success – at least with Iran.  Europeans may be more amendable to the idea, but the kind of substantive changes Trump would want (Indian and Chinese compliance) are probably not in the cards. 

The president is learning that sometimes, the reality as seen from the campaign through the prism of ideology is not the same as when confronted in the real world.