On January 29, Iran is reported to have test-fired a medium-range ballistic missile, prompting sharp condemnations from the Trump administration and a new round of sanctions designations. Many in Congress have pushed for further escalatory measures against Iran in reaction to its testing, though this would represent a dangerous course that could increase the likelihood of conflict with Iran and undercut the Iran nuclear deal, otherwise known as the Joint Comprehensive Plan of Action (JCPOA). As Congress and the new administration consider additional responses to Iran’s missile testing, it is worth keeping in mind the following:

Ballistic missile tests do not formally violate UN Security Council Resolution 2231

Pursuant to paragraph 3 of Annex B of UN Security Council Resolution 2231, the resolution endorsing the JCPOA, Iran is “called upon not to undertake any activity related to ballistic missiles designed to be capable of delivering nuclear weapons” including tests for a period that will last up to eight years. This is in contrast to the language in UNSC Resolution 1929 – which was replaced by UNSCR 2231 – which had declared that Iran “shall not undertake any activity related to ballistic missiles capable of delivering nuclear weapons.”

The specific language in UNSC Resolution 2231, which does not impose a binding legal obligation on Iran, was a compromise between Iran and the members of the P5+1. Members of the P5+1 were divided as to whether prohibitions on Iran’s missile activities should continue so long as Iran is in compliance with its JCPOA obligations, and viewed the inclusion of missile activities in prior UN Security Council resolutions as a means to pressure Iran on its nuclear program.

The Obama administration, and so far the Trump administration, have been deliberate in referring to Iran’s missile testing as “inconsistent” with UNSC Resolution 2231 rather than a formal violation. This is a formulation reflected by our allies in the P5+1, as well.

Legislating new ballistic missile sanctions threatens the JCPOA

Both the Obama administration and now the Trump administration have expanded sanctions designations in response to Iranian missile testing. This approach is not without risk – particularly for the Trump administration, which has no apparent backchannel with its Iranian counterparts to de-escalate heightened tensions.

However, new legislative proposals aimed at Iran’s ballistic missile program would impose broad based sanctions targeting whole sectors of Iran’s economy and would thus violate or significantly undermine the JCPOA. Such is the case with the “Iran Ballistic Missile Sanctions Act (S. 15),” introduced by Sen. Heller (R-NV), which would impose secondary sanctions on any sector of Iran’s economy that is directly or indirectly facilitating the development of Iran’s ballistic missile program – including, but not limited to, Iranian universities and its energy sector. That bill would likely result in reimposing sanctions that existed prior to the nuclear deal and would dwarf those prior sanctions, resulting in clear U.S. violations of the JCPOA. Heller’s bill was originally introduced in the previous Congress by former Sen. Kelly Ayotte (R-NH) and was supported by dozens of Republicans. Sen. Marco Rubio (R-FL) has introduced an umbrella Iran sanctions bill (S. 227) that contains the same sanctions.

Any sanctions legislation targeting Iran over its ballistic missile activities is likely to run into similar problems. While the Treasury Department has the resources and capabilities to designate specific entities for sanctions under existing authorities that do not necessarily undermine the JCPOA, Congress is largely constrained to broader efforts that would either be duplicative and unnecessary, risk re-imposing sanctions lifted under the nuclear deal, or otherwise violate U.S. JCPOA obligations not to interfere with the normalization of Iran’s economic activities. Particularly with a Trump administration that appears more inclined to over-respond to Iranian behavior that is perceived as threatening or provocative, Congress would be wise to show restraint instead of pushing forward escalatory legislation.

The U.S. will not succeed in sanctioning away Iran’s missile program

As eighteen prominent former policymakers and national security experts noted recently, while Iran’s  ballistic missile testing is a concern “we should not exaggerate the threat that testing presents to the security of the U.S. and its regional partners.” After all, the JCPOA has prevented the threat of Iran obtaining sufficient fissile material for a nuclear warhead that could eventually be fitted to an Iranian missile.

As a result, Iran’s missile program offers limited offensive utility, particularly in comparison to the firepower of the U.S., Israel, and Saudi Arabia. The U.S. remains the foremost military power in the world; Israel is believed to possess its own nuclear arsenal; and Saudi Arabia outspends Iran on its military 5:1. All have a modern air force, whereas Iran has been prohibited from purchasing new jet fighters since the Shah’s era due to sanctions.

Iran’s defense of its missile program is intrinsically tied to its experience during the Iran-Iraq war, when Saddam Hussein targeted Iran with missiles and chemical weapons with little to no international condemnation. Foreign Minister Zarif has stated that Iran needs its missile program “to prevent another Saddam Hussein around the corner attacking us with chemical weapons because the international community has failed miserably in protecting the Iranian people.” Whatever your views of such a position, it is one that has broad support within Iran across political divides.

Hence, Iran’s missile program is perceived as critical to its national defense as it offers some level of deterrence against attack. Given the centrality of the missile program to its defense doctrine, no amount of sanctions are going to convince Iran to part with it. However, if the Trump administration pursues a more diplomatic approach, it might find Iran willing to discuss certain confidence building measures, including limits on the range of its missiles. Iranian officials have indicated Iran is not interested in pursuing missiles with ranges greater than 2,000-2,300 kilometers, which would rule out intercontinental ballistic missiles (ICBMs).

The frequency of Iran’s missile tests is largely a continuation of past practices

Opponents of the JCPOA have been eager to portray an increasingly aggressive Iran after the nuclear deal, including by arguing that Iran’s missile testing has significantly increased in frequency. However, the pace of Iran’s missile testing has been largely consistent with past practices.

Michael Elleman of the International Institute for Strategic Studies noted in testimony before the Senate Banking Committee that from 2006 to 2012 – when nuclear negotiations had dim prospects – Iran test-fired approximately five missiles per year. During serious nuclear negotiations in 2005, 2013 and 2014, Iran test fired no ballistic missiles. Following the JCPOA, Iran fired three in 2015 and five in 2016. The latter half of 2016 contained no missile test launches, as noted by the UN report on implementation of Resolution 2231. The January 29 test represented the first in more than six months.