Controversy over Iran’s ballistic missile program intensified during the most recent round of talks between Iran and its six negotiating partners, the P5+1, or the five permanent members of the UN Security Council plus Germany, as the two sides disagreed over whether the topic should even be discussed. White House press secretary Jay Carney said in February that Iranians “have to deal with matters related to their ballistic missile program,” but Iranian Deputy Foreign Minister Abbas Araghchi rejected the notion, saying that Tehran would not discuss any issue besides nuclear matters. The subject of Iranian long-range missiles would appear to be so sensitive that it can be neither touched nor ignored.

Thus, it deserves a cautious and timely settlement. First the negotiators must take into account the Iranian missile program’s raison d’être, and in so doing address Tehran’s concerns. If they try to plow forward without doing so, they may end up harming the nuclear talks as a whole.

The Iranian missile program, despite its lack of precision as a pinpoint system, was developed as a conventional weapons program rather than a means of carrying nuclear warheads. In fact, the country’s longest-range missile would not even be able to cross all of Iran from Azerbaijan province in the northwest to the far reaches of Sistan province in the southeast, a distance of some 2,333 kilometers (1,450 miles).

Nonetheless, the missile program is an outgrowth of legitimate defensive needs. Historically it is a remnant of two things that occurred during the 1980-1988 Iran-Iraq war: the Iraqi use of Scud missiles against Iranian cities, and the US arms embargo.

During the war, the Iranian air defense system had the ability to intercept Iraqi airplanes and warn of their imminent attacks. Iraq’s long range-missiles, however, could escape such interception. Hence Iraqi missile strikes had the effect of surprise, large-scale terrorist attacks on major urban centers.

The US embargo on advanced arms, which prevented Tehran from obtaining fighter jets, long-range missiles, and missile defense systems, left Iran empty handed and unable to respond in kind to Iraq’s attacks. Iran therefore established a homegrown missile industry to counter the threat. Although the Iranian program was formed only later in the war and was much more limited in size and scope than Iraq’s, the continuation of the US ban on military imports provided enough reason for Tehran to continue its development.

Today the country continues to have valid regional defensive concerns. A comparison between Iran and its Arab neighbors to the south reveals a wide gap in the volume of modern weapon systems and technology. According to the Stockholm International Peace Research Institute,the Persian Gulf countries are among the biggest military importers of the world. They are led by Saudi Arabia, which ranks seventh worldwide in greatest military expenditure, having spent more than 56 billion dollars in 2012 alone. In contrast, Iran, due mainly to US and international restrictions, has since the Iranian revolution of 1979 been one of the lowest-ranked arms importers in the region—despite real threats from Iraq’s Saddam Hussein, Afghanistan’s Taliban, and terrorism.

Meanwhile the latest Military Balance from the International Institute for Strategic Studies, which annually assesses the capabilities of 171 countries, confirms that the Iranian Air Force’s equipment is out of date: Thirty-five years after the revolution, its main flying fleet still consists of American-made Phantom jet fighters that are desperately in need of spare parts to maintain—and if the air force is lucky, upgrade—their systems.

The interim agreement concluded in November, 2013 between Iran and the P5+1—the United States, China, Russia, Britain, France and Germany—opened a new chapter in the relationship between Tehran and the international community, one totally different from that of the past eight years. This transformation from a paradigm in which both sides constantly challenged each other to one of friendly collaboration, diplomacy, and problem-solving can’t be fully achieved in just a few rounds of negotiations. It can be accomplished gradually, though, if both sides embrace carefully thought-out policies. The recent resolution of the Syrian chemical weapons crisis, in which President Bashar al-Assad agreed to destroy his arsenal of the unconventional arms, was a product of high-level diplomatic collaboration between the United States, Russia, and Iran. Resolution of the debate over Iran’s long-range ballistic missiles could be next on the list of international diplomatic objectives, but will take more effort.

If the scope of the Iranian missile program is a real concern for the United States, then the issue deserves to be addressed in a thorough and balanced manner that respects Iran’s legitimate defensive needs. It will take time for such an approach to settle differences, and even longer to come up with constructive policies. A solution may not emerge until the later stages of final negotiations. But tackling the question of Iran’s long-range ballistic missiles must not be rushed.