In his speech to the United Nations General Assembly last week, U.S. President Donald Trump's contempt for the Iranian nuclear agreement was clear: The deal, he said, is "one of the worst and most one-sided transactions the United States has ever entered into ... an embarrassment." He is reportedly preparing for U.S. withdrawal from the agreement or its renegotiation, a demand that Iran has flatly rejected. While critics of the agreement are correct — it is not perfect — neither the U.S. president nor anyone else has articulated a coherent and credible alternative that does not make the situation worse. That alone is reason to stick with the agreement.

After two years of tough negotiations, six countries — Britain, China, France, Germany, Russia and the U.S. — along with the U.N. agreed with Iran in October 2015 to the Joint Comprehensive Plan of Action (JCPOA), a deal that imposes constraints on Tehran's nuclear activities in return for lifting some economic sanctions against that country. The deal was born of two sets of fears: first, that Tehran was committed to developing a nuclear weapon and second, that failure to reach a diplomatic solution would force countries to take military action to stop Iran and that would trigger a regional war.

The JCPOA caps Iran's centrifuge operations and slows the stockpiling of uranium needed to make a bomb. In return, the West lifted sanctions that had been imposed and which strained Iran's economy. Iran also got access to international oil and financial markets. Tehran's compliance with the deal is confirmed by intrusive inspections by the International Atomic Energy Agency.