How do you, some random person the web, actually KNOW that for sure, compared to the code-word classified intel that Trump will be getting (from several countries), for you to be able to say that Trump did this for "No Reason"?
Do you not think that maybe, just maybe, there's things that the President will know that we as the "public" aren't told, and that it's specifically done like that for a reason?
That was against Iraq (Operation Opera), with Iran they used the Stuxnet virus to ruin the centrifuges instead.
How do we know, because the US, everyone within the UN and everyone else involved said they were, the deal included having inspectors in and checking things. Also the deal was supposed to be strengthened over time to have stricter and better access for inspectors which would make it harder and harder over time. THat's how these deals often go, first stage, big deal. Most of their sites stop producing/working on it but they have a few smaller pieces and everyone else probably knows. But it's good first step, we let some of your people in, essentially it's building trust. If they decommission everything overnight then the UN change their mind and slam on massive sanctions or even start pushing for a war then they aren't caught out. Both sides want to build trust and it happens in steps.
So after several years of both sides holding up their end of the bargain then they renegotiate, the west has more access, Iran step down their programs further, and get something in return, reduced sanctions, a deal to pay for a nuclear power plant built by a UN approved group with massive oversight, etc. That's how the world works. Everyone else was clear with what was going on, everyone else was talking about renegotiating and making a stronger deal that is better for everyone. So at worst, what the US should have done is brought such a new deal forwards and pushed for harder terms than everyone had originally planned, instead they backed out of the deal and haven't at all tried to make a stronger deal. As before though, and this is the point, this is what diplomatic relationships are, building trust. Strengthening a deal everyone was sticking to every few years is how relationships are built and peace is found, how you break trust and make future deals much much harder, is breaking deals without cause. If the US tried to make a new deal now what reason does Iran have to trust they'll stick to their part of it?
Also no, for everything the president and Bolton/etc have said on Iran, none of them actually said anything about Iran weren't sticking to it, almost all their excuses were nonsense about how bad the deal was and how much cash Obama paid them. If they could have simply said Iran are breaking the deal so it's over, they would have AND their intelligence would have shared that with all the other countries involved in the deal and instead none of them broke it. This was a purely Trump and his warmongers action based on the fact that they want tensions higher as peace is bad for profit.