(nytimes) -- On a crisp morning in Vienna two summers ago, hours before concluding the nuclear deal with the United States, the European Union and five other world powers, I took to Twitter to write that the landmark accord was “not a ceiling but a solid foundation.”

Unfortunately, for the past 11 months, the response to Iran’s good faith has been tantrums from the Trump administration. But the unreliability of the United States — from climate change to Palestine— has become predictable. Our main concern now is cautioning European countries against wavering on issues beyond the scope of the nuclear agreement and following in lock step behind the White House. As the nuclear deal and the Middle East enter uncharted and potentially combustible territory, it is imperative that Europe helps ensure that we don’t soon find ourselves repeating history.

More than a decade before the talks that led to the 2015 nuclear deal, Iran held similar negotiations with Britain, France and Germany. European diplomats, seeking to persuade George W. Bush’s administration to give diplomacy a chance, asked us for a temporary, voluntary freeze on uranium-enrichment-related activities as a confidence-building measure. We agreed.

But placating the Americans proved difficult, and the Europeans took another wrong turn. After two years of negotiation — and under pressure from the United States — Britain, France and Germany suddenly demanded that we abandon all enrichment activities. The talks fell apart and the Europeans ended up neither stopping our nuclear program nor appeasing Washington.

Sporadic talks in the intervening years went nowhere, and by 2013, when we sat down again to negotiate — this time directly with the United States, as well — Iran had increased its number of centrifuges to 20,000 from fewer than 200 in 2005. There was no longer talk of an end to uranium enrichment on Iranian soil.

The nuclear deal is a rare triumph of diplomacy over confrontation. Undermining that would be a mistake. Europe should not pander to Washington’s determination to shift focus to yet another unnecessary crisis — whether it be Iran’s defensive missile program or our influence in the Middle East. This would repeat the very dynamics that preceded the nuclear deal.

Let me reiterate: Iran’s military capabilities comply with international law and are entirely defensive. Our defensive posture stems from sober geostrategic calculations, as well as moral and religious convictions. Our military doctrine is also based on historical experience: During the Iran-Iraq War, Saddam Hussein rained Soviet-made missiles on our cities, some of them carrying chemical components provided by the West. The world not only kept silent, but also no country would sell Iran weapons to enable us to at least deter the aggressor.

We learned our lesson. We have honed missiles as an effective means of deterrence. And our conscious decision to focus on precision rather than range has afforded us the capability to strike back with pinpoint accuracy. Nuclear weapons do not need to be precise — conventional warheads, however, do.

Our commitment to self-defense is not a slogan. We have deployed our missiles against only a few equally heinous adversaries: Saddam Hussein’s regime and its terrorist allies, and the so-called Islamic State. And our strikes came in response to their merciless killing of Iranians.

No Iranian administration will leave our people defenseless. The international community — and Europe in particular — should realize this and instead focus its efforts on tackling real threats to the world, like the wars engulfing the Middle East.

Iran is proud of taking the lead in trying to bring an overdue end to the bloodshed in Syria. In 2013, I presented a plan to end the conflict there through a cease-fire, the formation of a national unity government, constitutional reform and free and fair elections. But this plan fell on deaf ears. Still, we have continued our efforts. Just last month, our president, Hassan Rouhani, joined by his Russian and Turkish counterparts, took an important stride toward peace at their summit meeting in Sochi, Russia, paving the way for more aid, de-escalation and the convening of a Syrian people’s congress.

In the case of Yemen, only two weeks after Saudi Arabia began its brutal bombing campaign in April 2015, Iran put forward a plan urging an immediate cease-fire and humanitarian assistance, followed by national dialogue to establish an inclusive government. The perpetrators of the humanitarian crisis, and their Western allies, choose war instead.

As Iran and its partners labor to put out fires, the arsonists in our region grow more unhinged. They’re oblivious to the necessity of inclusive engagement. And yet, despite the huge stakes, important stakeholders remain reluctant to hold the arsonists to account.

We urge responsible parties to recognize the need to look forward. And so, let us find hope in a shared vision of a more peaceful future and be brave enough to take tangible action to make it happen. In these pages in 2015 , I presented a proposal for a regional dialogue forum, a way to bring Iran and its neighbors together to work toward peace. We’re hopeful that responsible actors outside the Middle East will focus their efforts on urging their allies in our region to take seriously our proposal. We believe it can be a good start, and we once again invite all of our neighbors to participate.

(Image: Alex Nabaum)