It doesn’t matter what you call it. As you said it was an agreement. The agreement was working according to our own intelligence agencies and our allies that were also parties to the agreement. The agreement didn’t have a clause that allowed one party to unilaterally void it. Here, I will let Fox News explain it to you.
If you don’t believe Fox News, I suggest you try it in your own personal life. Call your auto loan holder, your mortgage holder, your landlord, your credit card company or whomever else you owe money to and say, “I will no longer be sending you payments because I have opted to void our agreement.” I don’t think it will work out so well for you.
The money wasn't ours, to begin with. It was Iranian money that had been trapped here in U.S. banks when we imposed sanctions on them. We allowed them to access money that already belonged to them. We didn't give them anything.
The U.S. loses because Trump was made a fool of on the world stage. Our so-called great negotiator gave up a bird in the hand (The Iran Agreement) for one in the bush that didn't pan out. All the right-wing outlets up until yesterday were praising this as some sort of great accomplishment and saying Trump should get the Nobel Peace Prize. Trump himself said "some people are saying" I should get a Nobel. Instead of the Nobel, Trump was left sucking on the turd Kim Jong-un shoved into his mouth. Around the world the withdraw from the Iranian agreement (one that was working) and the pursuit of an agreement with Kim Jong-un who was just stringing Trump along is seen as a complete collapse of U.S. Foreign Policy.