Stephen Crabb is Member of Parliament for Preseli Pembrokeshire.

Later today, I will be leading a Westminster Hall debate on Iran’s nuclear programme and the future of the so-called Joint Comprehensive Plan of Action (JCPOA) nuclear deal which was struck in 2015. It is a deal that has fundamentally failed to curtail Iran’s nuclear activities and as things stand today, Iran is a threshold nuclear weapons state.

The much-feted JCPOA was celebrated for supposedly pushing Iran back to having a 12-month timeline to secure a nuclear weapon. Most estimates now indicate the Islamic Republic is a mere two or three months away. The JCPOA’s very utility is now in question.

Today’s debate comes after a year of provocative regional actions and sustained, systematic violations of Iran’s nuclear commitments under the JCPOA nuclear deal. Each of these actions have been made in the face of a Biden administration that is expressly seeking engagement and de-escalation.

Iran’s bellicosity is evident throughout the Middle East region. This year alone, Iran has killed both a British national and British serviceperson in its shadow bombing campaign against oil tankers navigating international waters, and drone and missile strikes on allied forces in Iraq. Iran also played a central role in Hamas’s deadly rocket assault on Israel in May which led to another terrible ‘round’ of conflict.

Make no mistake, Tehran had its hands in the shocking battles in Beirut last week which raised the distressing possibility of a much-feared civil war in Lebanon.

Wherever Iran exerts influence, it destroys the very viability of fragile but sovereign nation states and fans the flames of ethnic, sectarian, and political division within each society for its own gain. From Iraq and Lebanon to Syria and Yemen (and beyond), it has left a trail of violence and destruction.

And yet, Iran’s violent ambitions have never been confined within its near neighbourhood. An Iranian diplomat was recently sentenced to 20 years in prison for his involvement in a foiled bomb plot against an Iranian opposition rally in Paris in 2018. The event was attended by a number of British parliamentarians – including the late Sir David Amess, who was a committed, powerful supporter of democratic revival in Iran.

Sir David had a deep personal interest in the Middle East and understood better than most that dialogue with people of other faiths and none would serve to create a better world. Long before the emergence of the landmark Abraham Accords signed between Israel and the UAE and Bahrain, Sir David was proving that being a friend of Israel didn’t preclude you being friends with Israel’s Arab neighbours. He led the way, and I hope many more will follow him.

Iran’s nuclear violations this year represent a complete abrogation of its JCPOA responsibilities. Simply, they have no credible civilian application: installing advanced centrifuges; obstructing IAEA nuclear inspectors from undertaking their crucial work; enriching uranium to 60 per cent (Iran is only permitted to enrich to 3.67 per cent); and the production of uranium metal, which is a significant component of nuclear weapons.

And yet, despite this deliberate escalation of nuclear violations, there has been a strikingly muted response from the P5+1 nations. The UK – alongside France and Germany have issued a series of statements expressing “concern” with adverbs of gradually increasing strength. In no way is this sufficient to give Iran’s regime cause to rethink.

I fear that this inaction has led to ever-greater acts of defiance and escalation. Our collective failure to reprimand Iran for each acceleration of its nuclear programme underwrites its next transgression. It makes one think what other malign nuclear actors, and would-be nuclear actors, will be learning from Iran’s nuclear brinkmanship.

As a party to the JCPOA nuclear deal, the UK has a critical role to play. To this end, I welcome the Foreign Secretary’s comments this month about working “night and day with our friends and allies across the world to stop” Iran from becoming a nuclear power. This is an unmistakably important commitment. As I listened to the Foreign Secretary’s recent remarks about Iran and the need for a “network of liberty”, I couldn’t help but think that it is now more important than ever that we make a concerted multilateral push against Iran.

There are a number of diplomatic levers at our disposal which we must now pull before it is too late.

Foremost, the international community must send a decisive signal to Iran next month at the IAEA’s Board of Governors final quarterly meeting of the year. The UK, alongside our European allies, must push for a motion of censure for Iran’s continuing non-compliance with IAEA verification of its nuclear activities. We must not miss this opportunity.

Beyond this, the UK should consider going one step further than its January 2020 triggering of the Dispute Resolution Mechanism. It is, perhaps, now time for the UK – alongside international partners – to refer the Iran file back to the UN Security Council and to consider “snapback” of prior sanctions.

While sanctions are far from the panacea presented by some advocates, it is undeniable that the financial implications of sanctions were pivotal in bringing Iran to the negotiating table in the first place.

Iran’s nuclear advancements cannot be unlearned. They have set a new baseline. Accordingly, in any return to the JCPOA the UK must work with partners to secure supplementary nuclear restrictions to compensate for the reduction in Iran’s nuclear breakout time. Destruction of advanced centrifuges will be key, and the IAEA must be empowered to have unfettered access.

Iran is precipitously close to crossing the ultimate red-line. We can ill-afford to blink now.