Iranians celebrate on a street in northern Tehran, on April 2, 2015, after Iran's nuclear agreement with world powers in Lausanne, Switzerland. (Ebrahim Noroozi/Associated Press)

The writer is the foreign minister of Iran.

Nearly three years ago, the newly elected Iranian president called for constructive engagement on a momentous undertaking: resolving the nuclear crisis dividing Iran and the West. The fruit of 22 months of unprecedented diplomacy — the historic Joint Comprehensive Plan of Action (JCPOA) — was formally implemented in January. Yet despite this important achievement, the worrying reality is that we now face a far greater challenge.

Those who once hid behind the smokescreen of the artificial crisis over my country’s peaceful nuclear program have stepped up their damaging adventurism. Driven by desperation, they have resorted to measures that all of us will have to live with over the coming years and, possibly, decades. Allow me to explain.

Some of those who agitated against the JCPOA were blatant in their efforts to drag the region into yet another disastrous war. They did — and continue to do — their utmost to convince their Western allies to return to the broken taboo against engaging with Iran. They have repeatedly resorted publicly to raising the specter of military — even nuclear — attack on my country, in blatant disregard for international law.

Others have been less blatant. Amid their backroom efforts to thwart the constructive engagement between Iran and six world powers, they resorted to a rapid build-up of their already excessive military hardware. Alarmingly, some also boosted their support for militant extremism, in the belief that it could serve as a tool to achieve short-term political aims. The disastrous outcomes of these efforts are clear for all to see.

Having spent a staggering amount of their peoples’ petrodollars on weapons-hoarding, these actors are now seeing their literal, and political, fortunes plummet in step with oil prices. Meanwhile, the extremist lost souls they have empowered are no longer terrorizing only others in the region and the wider world but are also biting the very hands that feed them.

Perplexingly, amid these disturbing developments — including the recent tragedies in Paris and Brussels — the West does not appear to be focused on joining hands to eradicate militant extremism. Neither is there much discussion of how a country such as Saudi Arabia has become the world’s third-biggest military spender, overtaking Russia. And rather than focusing on how Yemen was bombed to rubble for 12 relentless months — and thus turned into a tinderbox of famine and poverty and a breeding ground for al-Qaeda — scare-mongering about Iran and its defensive capabilities is back in full swing.

During the intensive negotiations over complex issues surrounding Iran’s nuclear energy program, my country insisted at every turn that our defenses were not on the table. But our argument was not centered on sovereignty, nor on the fact that our military is vastly outspent by those of many of our Western-allied neighbors. We simply made reference to the recent past.

In 1980, in the aftermath of the Islamic Revolution, Iraq’s Saddam Hussein launched a war against Iran fully supported financially and militarily by almost all of our Arab neighbors and by the West. Unable to secure a quick victory, Hussein used chemical weapons against our soldiers and civilians. The West not only did nothing to prevent this, but it also armed Hussein with sophisticated weapons, while actively preventing Iran from getting access to the most rudimentary defensive necessities. And during the eight long years that this war continued, the U.N. Security Council did not issue a single condemnation of the aggression, the deliberate targeting of civilians or the use of chemical weapons.

This may have been forgotten by most in the West, but it is not forgotten by our people. They remember the missiles raining down, the horrific images of men, women and children murdered with chemical weapons and, above all, the lack of a modern means of defense.

On top of this, having listened to the outdated U.S. mantra of “all options are on the table” for 37 years, our people understand that we need to be prepared to prevent that illegal and absurd threat from ever becoming a reality.

The words “never again” resonate with Iranians, too.

It is against this backdrop that we develop and test our indigenous defensive capabilities. We have no other choice, as we continue to face major hurdles in fulfilling our military hardware needs from abroad, even as our neighbors procure such hardware in mind-boggling quantities. Indeed, our military budget, for all the alarm raised by the West whenever we test a new system, is a small fraction of what is spent by our neighbors, which have a fraction of our territory or population to defend.

Iran is blessed. At a time when bombs go off in public places throughout the Middle East and war is at our doorstep, we have a stable, safe and healthy environment for our citizens and for those visiting and doing business with us. This is due to both the vigilance of our government and the character of our people. We take pride in using our resources for universal health care and education and advanced science and technology rather than wasteful military spending. Our people want nothing more than peace and cooperation with our neighbors and the world at large. We have not launched a war in more than two centuries and continue to make an unequivocal commitment of never commencing such foolishness. We challenge all our detractors — large and small — to commit likewise.

I urge my counterparts around the world to reflect on what has been achieved through diplomacy rather than threats, sanctions and demonization. Today, Iran, for millennia a vital bridge between East and West, remains the most stable, safe and inviting stop along our stretch of the Silk Road. My government remains committed to constructive engagement and my initiative for a regional dialogue forum. A window has opened, and we hope our counterparts will seize on the opportunity it brings so that we may all return our focus to shared objectives and challenges.