the Iran game

It's clear that President Trump wants to scrap the Iran nuclear deal, formerly known as JCPOA. By mid-October, he is supposed to tell Congress whether or not Iran is complying with the agreement. Despite IAEA findings of technical compliance, Trump and many in his administration view the agreement as flawed and Iranian behavior outside the nuclear provisions as unacceptable.

So what will he do? There's a good analysis of the options in a new CRS report. 
Rather than claiming violations which other countries will not agree with, I believe he will take the easier path that still preserves his options down the road. Instead of certifying anything, compliance or noncompliance, Trump may just refuse to send any report to Congress. That would allow Congress to vote to re-impose sanctions lifted as part of the deal.

In fact, Congress could easily do that, because the law negotiated with the Obama administration allows prompt floor action in both House and Senate, no amendments, and time-limited debate. Opponents in the Senate can't filibuster or force a supermajority vote. This approach shares responsibility for such a major decision. [I personally believe continued adherence to JCPOA is in our security interest, but I bet the White House takes this path.]