MAGA clearly refers to when America did not stand by her treaties and agreements. Just ask Native Americans an the numerous treaties regarding their lands until they were pushed off the best lands and left only small pieces the whites did not want.
The Joint Comprehensive Plan of Action was an agreement including the US, UK, France, China, Russia and Germany. Trump's removing the US from this international agreement does not set a good precedent. It not only proves the United States will not stand by its agreements, but that it also does not trust some of our closest allies.
And yet Trump claims that when he makes promises he keeps them (except when they include being faithful to his wives or representing the American people). The majority of Americans wanted to stay in the deal.
But Trump is in deep trouble with porn stars and concerns that Mueller will prove collusion, so he needs a war and now he has Iran. A war with Iran would cause gas prices to skyrocket, a win-win for oil companies and Saudi Arabia, but it would not be good for our young people who will be asked to die for the cause.
Trump claims that Iran is a leading sponsor of terrorism, and yet Iran is fighting against Daesh (ISIS) and Al Qaeda. Not a single terrorist attack on US soil has been traced to Iran, but most of the 9-11 terrorists were from Saudi Arabia and others were linked to the terrorist organizations that Iran is fighting.