As we approach the October 18 expiration date of the arms embargo on Iran under U.N. Resolution 2231, which endorsed the Iran nuclear deal, the United States has embarked on a tough and tedious journey towards indefinitely extending the embargo. Secretary of State Mike Pompeo has offered the European members of the U.N. Security Council, as well as China and Russia, two options: either adopt a new resolution extending the arms embargo or the U.S. will use the snapback mechanism in the JCPOA to re-impose U.N. sanctions on Tehran.

The draft U.S. resolution originally called for imposing a permanent arms embargo on Tehran. However, in its latest move, Washington has revised its draft resolution in a bid to gain enough support at the Security Council, where it has faced strong opposition from veto powers China and Russia. While the original U.S. resolution was bound to fail, the U.S. has softened its voice, and in the significantly shortened new resolution it says the arms embargo “shall continue to apply until the Security Council decides otherwise.”

Iran has threatened that it will react severely should the U.S. succeed in extending the arms embargo in violation of the nuclear agreement. Full withdrawal from the JCPOA and even the Non-Proliferation Treaty are options that Iran has said are on the table. President Rouhani and other Iranian officials have strongly warned against such a U.S. move.

Europe, China, and Russia have also suggested that they will not support the U.S. move, and that the United States cannot invoke the snapback mechanism because it is no longer signatory to the JCPOA.

Iran has been under tough sanctions since the U.S. withdrawal from the JCPOA in May 2018, and has been denied the benefits of the deal ever after. The removal of the arms embargo is one of the few remaining advantages of signing the JCPOA, and is of great importance to Tehran. The U.S. attempt to use the snapback mechanism and trigger the return of U.N. sanctions in violation of Resolution 2231 is intolerable for the Islamic Republic for several reasons.

First, Iran sees its exit from the Chapter VII of the U.N. Charter and the lifting of related sanctions as its greatest achievement in signing the JCPOA. From Iran’s viewpoint, being under Chapter VII would be detrimental to the survival of its political system, because any country that is under such status is considered to be a threat to international peace and security.

Tehran maintains that being placed under Chapter VII could result in a war, as can be seen in the cases of Iraq and Libya.

Second, the extension of Iran’s arms embargo would provide legal basis for the necessity of including Iran’s ballistic missile program in a new nuclear deal with Iran as the Trump administration wishes. Iran has consistently insisted that the JCPOA was limited to nuclear issues, and that it will never engage in negotiations on its missile capabilities, which form the bulk of its defense and deterrence doctrine.

Tehran believes it has an inalienable right to develop defensive weapons. Since Iran is not a part of any defense and security coalition in the Middle East and none of the major powers has guaranteed its security, strengthening its defense power is crucial. The Iranians tend to recall the experience of defending the country against Saddam Hussein’s Iraq in a devastating eight-year war to highlight their need for developing a home-grown defensive program.

Finally, Iran sees Resolution 2231 as an integral part of the JCPOA as it legitimizes the deal. Therefore, violating the U.N. resolution would be a serious breach of the international accord. In other words, any breach of the U.N. resolution would imply that the deal has lost its global support.

There are consultations underway between Russian, Chinese, and European diplomats to resolve the tensions over extending Iran’s arms embargo and to eliminate the risk of a JCPOA collapse.

If the resolution to extend the Iran arms embargo fails and the United States triggers a return of the U.N. sanctions against Tehran, the U.N. Security Council would face a big challenge. The UNSC will be divided into two groups: The U.S. and its supporters, and the remaining signatories to the deal that differ in interpreting the Resolution 2231. There would be a legal battle between them. The U.S. and some of its allies would argue that U.N. Security Council sanctions and previous resolutions against the country are back in place and that nations are obliged to comply with them.

The second group, which includes the European countries, China, and Russia would argue that because the United States is no longer a participant in the JCPOA, its action in using the trigger mechanism is illegitimate, the U.N. sanctions would not be re-imposed, and Security Council Resolution 2231 would remain in place.

If the U.S. resolution is passed or the U.N. sanctions are reinstated through the snapback mechanism, a serious debate will emerge among Iranians as to what would be the benefits of staying in completely fruitless nuclear deal. When President Rouhani’s greatest security and political achievement, the JCPOA, is actually destroyed, it will make no sense for Tehran to adhere to its obligations. Iranian foreign policy makers would face a tough question on what the consequences might be of not responding to this U.S. action.

Many believe that if Iran does not give a decisive response, it would be seen as a sign of weakness and Tehran would be pushed to negotiate non-nuclear issues such as ballistic missiles and its influence in the region. This would all happen despite the fact that other remaining parties to the JCPOA including Europe, Russia, and China will have done nothing to make up for Iran’s losses following the U.S. actions.

In that case, Iran would be very likely to change its nuclear doctrine and would take serious steps out the nuclear deal. However, it will be very difficult for Iran to figure out how to respond to the U.S. action appropriately and seriously while still leaving the door open for a possible compromise until the upcoming U.S. presidential elections arrives. Perhaps if Democratic contender Joe Biden is elected, he will take a different path, and hopes for the revival of JCPOA would rise again, or more immediately, the actions taken by the Security Council would be reversed.

Iran’s possible options would include suspending the voluntary implementation of the JCPOA’s Additional Protocol, resuming enriching uranium at 20 percent at the Fordow underground nuclear site, and significantly reducing IAEA inspections of its nuclear activity, all of which would mean the rapid expansion of Iran’s nuclear program without IAEA monitoring, which, in turn, would spark widespread reactions. Nevertheless, it is likely that Iran would not hurry and instead would take these steps gradually.

In addition, these measures would give Iran more leverage in possible future negotiations as similar moves helped it to achieve advantages in the JCPOA in 2015.

Beyond these steps, the full withdrawal from the JCPOA and even the NPT would remain options available for Tehran, though it is highly unlikely that it would go this far in the short run.