President Obama on Wednesday all but admitted he's either unwilling or unable to lead the free world.

When it comes to the nuclear deal with Iran, which is already being described as a "signature" diplomatic achievement for Obama, the commander in chief said the U.S. has no choice but to follow the international consensus.

That consensus says: Give Iran a break on its nuclear program, end the conventional arms and ballistic missile embargoes in a few years, and let's start trading with Iran, despite all those "death to America" chants and the four Americans it holds hostage.

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At his lengthy White House press conference, Obama was asked about language in the deal that ends the arms embargo against Iran after five years. Obama said that provision was needed because the rest of the world is ready to trade with Iran, and there's nothing he or America can do about it.

In the past, he said, sanctions "required the cooperation of countries all around the world." But that consensus appears to have dissolved, and Obama offered no plan for trying to convince those countries to see things differently.

Why do they want to open up to Iran? Because many of them "really want to purchase oil from Iran."

That desire is understandable, he said, because the sanctions so far have "cost them billions of dollars." Before, those countries were willing to play along with the U.S. because "they've believed we were sincere about trying to resolve the nuclear issue peacefully."

But now the world has spoken, and it's time for the U.S. to follow along and lift the sanctions, just as everyone else is doing. Obama said if the U.S. doesn't, the U.S. just won't fit in anymore.

"If they saw us walking away, or more specifically, if they saw the U.S. Congress effectively vetoing the judgment of 99 percent of the world community that this is a deal that resolves the ... nuclear weapons program in an equitable way, the sanctions system unravels," he said.

Even if the U.S. dared to stake out its own position by rejecting the deal and imposing unilateral sanctions, it wouldn't matter that much, he said. Here, Obama completely discounted the moral value of U.S. leadership by saying it wouldn't be seen as leadership at all, and implied that the only impact would be to take away a few billion dollars from Iran.

"So maybe they don't get $100 billion; maybe they get $60 billion or $70 billion instead," he said.

Since Iran is still "getting some cash windfall" no matter what the U.S. does, the U.S. might as well hang with all the other countries doing the same thing.

"We've lost credibility in the eyes of the world," he said of the option of going it alone. "We will have effectively united Iran and divided ourselves from our allies. A terrible position to be in."

Is it really impossible to convince other countries? That appears to be Obama's admission, and his excuse. Stunningly, he said he has no leverage on the world stage to get a better deal, one that would eliminate all of Iran's nuclear capacity.

"[T]here is nobody who thinks that Iran would or could ever accept that, and the international community does not take the view that Iran can't have a peaceful nuclear program," he said.

"And so we don't have diplomatic leverage to eliminate every vestige of a peaceful nuclear program in Iran."

Yes, the issues are difficult. But like the deal or not, Obama's remarkable explanation was that of a prostrate president. One who says it makes no sense to push for the return of Americans held captive in Iran. One who offers concessions to Cuba in return for nothing. One who fends off Russian aggression with words, but not arms for Ukraine.

As Obama said, a terrible position to be in.