Last fall Iranian President Hassan Rouhani traveled to United Nations headquarters in New York to reassure the world of Iran's peaceful nuclear intentions and to seek "better relations" with the United States, a "great nation." In late November, Iran signed an interim agreement with the G-5 plus 1 (U.S., Russia, China, United Kingdom, France, Germany), supposedly assuring that it would not try to develop a nuclear arsenal.

But last month, President Rouhani appointed as Iran's new U.N. ambassador a man identified as a spokesman for the "students" who took American diplomats hostage in 1979. As one unidentified U.S. official remarked, the appointment looks like an "intentional provocation" of the United States.

It has certainly been treated that way. Although former President Jimmy Carter, who lost his bid for re-election in 1980 in part because of the Iranian hostage crisis, says it would be "inappropriate" to deny a visa to the new Iranian ambassador, Hamid Aboutalebi, and the U.S. is obligated by treaty to admit U.N. diplomats, White House spokesman Jay Carney said Tuesday that the appointment was "not viable."

In effect, Mr. Carney was asking Iran to withdraw the appointment. Iran has refused to do so.

The White House took that position only after the Senate unanimously passed a bill denying a visa to the Iranian diplomat. The bill is now before the House. However, even if it passes, the United States probably cannot prevent Iran's new ambassador to the U.N. from taking his seat in compliance with the U.N. treaty.

What accounts for the change in the tone of Iranian overtures to the United States?

One clue comes in the way Iran's access to foreign trade has improved since the interim nuclear deal reached in Geneva, the fruit of President Rouhani's diplomatic offensive in September.

That deal was meant to set back Iran's ability to "break out" from a peaceful nuclear accord. Break-out time is the period required to produce enough enriched uranium to make a nuclear weapon.

The partial lifting of sanctions on Iran has reportedly improved its foreign trade by $7 billion. Oil exports have risen to one million barrels a day.

A sanctions-busting deal is in the works with Russia that would increase oil exports by another 50 percent in a barter exchange that could see Iran getting weapons and nuclear equipment in exchange. Other nations have shown they are eager to make deals with Iran.

So Iran's economic gains from the interim deal have been substantial - and if sanctions erode further they could be even more so.

Earlier this week, Secretary of State John Kerry told the Senate Foreign Relations Committee that Iran could now reach "break out" in just two months. Is this what President Obama considered acceptable enough to loosen sanctions?

Contradicting other administration claims that a permanent deal can be reached by June 20, when the interim deal expires, Mr. Kerry said he was neither optimistic or pessimistic.

In other words, he does not know if a deal can be made. Committee Chairman Robert Menendez, D-N.J., complained that even a permanent deal might buy only a year of break-out time, and that it takes considerably more than a year to put strict sanctions in place.

Iran's "intentional provocation" in the choice of a U.N. ambassador seems to be a signal that President Rouhani no longer cares whether he has good relations with Washington.

He may, with good reason, think he no longer needs to worry about it.

And that should give U.S. officials ample reason to re-evaluate what increasingly appears to be a fool's bargain on Iran's nuclear program.