From the New York Times, I'm Michael Barbaro. This is The Daily.

Today, President Trump withdraws from the Iran nuclear deal, calling it decaying and rot.

So why did President Obama sign onto it in the first place?

It's Wednesday, May 9.

Today, after two years of negotiations, the United States, together with international partners, has achieved something that decades of animosity has not.

A comprehensive long-term deal with Iran that will prevent it from obtaining a nuclear weapon.

Mark Lander, remind me why President Obama signed this nuclear deal with Iran in the first place.

When Barack Obama came into office, Iran was getting uncomfortably close to having the capacity to develop a nuclear weapon.

And this was unnerving its immediate neighbors, its neighbors in the region like Israel, as well as the Europeans.

So what President Obama decided to do was to get Iran to come to the table and agree not to force where having a nuclear program for all time, but to agree to a pause in the program, to agree to curb activities related to developing a weapon for some period of 10, 20, 25 years that would buy the world time to deal with the threat of Iran without the specter of them having a bomb in a year or even three months.

I strongly believe that our national security interest now depends upon preventing Iran from obtaining a nuclear weapon, which means that without a diplomatic resolution, either I or a future U.S. President would face a decision about whether or not to allow Iran to obtain a nuclear weapon or whether to use our military to stop it.

But simply, no deal means a greater chance of more war in the Middle East.

So the United States banded together with its three major European allies, Britain, France, and Germany, as well as China and Russia, and together this group of five countries sat down with Iran over a period of many months and hammered out the terms of what is known as the joint comprehensive plan of action.

And everyone understood at the time it was announced that this was not a perfect deal. It was limited both in scope and limited in how long it would last.

Okay, so what specifically does the deal not do that helps explain how we got to where we are today?

Well, several issues were carved out of the negotiation, and that has fueled the argument of critics like President Trump.

One of the first and key areas was Iran's ballistic missile program. It is not included in the deal. Iran can continue to develop and test ballistic missiles. It is not restricted in doing so.

And those were the missiles that theoretically could carry a nuclear weapon. That's right. And they were left out.

They were left out. This was a very fought over point. The Iranians didn't want them to be included, and the West, John Kerry and others agreed to that.

We are actually capitulating to the global superpower of terrorism, which is Iran.

The second major area is Iran's behavior in the region.

They are the number one sponsor of terrorism around the world. They are sponsoring terrorist activities in Yemen, in Syria.

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