The Trump administration’s attempts to isolate and demonize Iran for all the ills of the Middle East will do far more harm than good to long-term US interests. Instead of seeking to isolate and confront Iran, the administration should build on the Joint Comprehensive Plan of Action (JCPOA) to ease the region’s sectarian and other conflicts and avoid further destabilizing the local security architecture.

By not leaving diplomatic space for Iran and its Arab neighbors to manage their differences, President Trump has set the United States squarely alongside the Sunni House of Saud on a collision course with the Shi’ite Iranian regime. This is precisely what the Obama administration tried to avoid (albeit with little success) by concluding the JCPOA and trying to lighten Washington’s footprint in the region, thereby encouraging Tehran and Riyadh to find an equilibrium both could find acceptable.

Trump’s “new” approach is really a repackaging of an old idea: that isolating and chastising Iran will somehow produce peace and security for Washington’s partners and allies. To that end, the Trump administration has promised to sell more military hardware to Saudi Arabia — a country that has exported the most intolerant and virulent form of Sunni Islam to all corners of the earth. The state-sponsored hardline Islamism promulgated from Saudi Arabia has provided the ideological foundation for groups such as the Islamic State and al-Qaeda.

As Trump was denouncing Tehran in a major speech in Riyadh, Iranians were holding consequential elections on their future.  While elections in Iran are not open by Western standards, they are a far cry from the Saudi monarchy’s hereditary and authoritarian rule. A policy of US hostility toward Iran will weaken, not strengthen democratic forces in the region.

As the recent ISIS attacks in Tehran have shown, Iran is very much a target for the same type of terrorism that has struck Paris, Brussels, Berlin, Manchester and London – as well as the United States. Indeed, the attackers appear to have returned to Iran from fighting on the side of ISIS – and against US-led forces – in Syria and Iraq. However, the Trump White House seems to have little appreciation for these nuances and reacted to the bloodshed in Tehran with a churlish statement that blamed Iran for its own victimization.

More sophisticated weaponry provided to Saudi Arabia by Washington will not make Tehran cower. In fact, it will have the opposite effect by pushing Iran to accelerate its ballistic missile program while spending only a fraction of what US allies do on defense. It also presents Russia and China with an opportunity to further fuel the regional arms race by selling more weapons to Iran.

Furthermore, Iran can project hard power beyond its borders in Syria, Iraq, Lebanon, Yemen and Afghanistan. Its armed forces are tested and battle hardened and have spent decades grooming militias among Shi’ite Arab and South Asian populations. The Saudis on the other hand, after two years of steady bombing and decades of military purchases from the West, are struggling to defeat Houthi rebels in Yemen who have only minimal Iranian support. The Saudis and others continue to finance radical Sunnis in a spiraling proxy war with Iran-backed groups. It is no coincidence that four of the top five countries of origin for ISIS recruits are also Washington’s top Sunni-majority military partners in the Middle East – an issue that got no mention during Trump’s trip to Saudi Arabia. Those countries were also not included in Trump executive orders seeking to limit travel and immigration to the US from the Muslim world.

A wholesale US embrace of the Sunni narrative will also have terrible consequences for American operations in Shi’ite-led Iraq. It is no secret that Iranian-backed militias are on the ground fighting ISIS, nor that Tehran has great influence in Baghdad. Bellicose US rhetoric could fracture this already-fragile coalition and further alienate Shi’ites in the Middle East, who make up sizable minorities – and in the case of Bahrain, a majority — in many countries in the Persian Gulf and Levant.

Trump’s discourse in Riyadh was reminiscent of President George W. Bush’s 2002 State of the Union address to Congress in which he labeled Iran part of an “axis of evil.” From that moment forward, Tehran ceased previous quiet efforts to help stabilize both Iraq and Afghanistan, and began actively spoiling against Washington. Iranian elites started to believe that their government was a new target for “pre-emptive” regime change following Saddam Hussein, and Iran deployed Shi’ite proxies against US troops in Iraq.

In negotiating the JCPOA, Iran and the P5+1 – the five permanent members of the UN Security Council plus Germany – consciously chose to stick to nuclear matters and not seek a broader grand bargain. The Trump administration and members of the US Congress have every right to oppose other Iranian policies but not in a way that threatens to unravel the nuclear deal and exacerbate regional conflicts.

So far the Trump approach has emboldened Saudi Arabia to try to isolate the tiny emirate of Qatar, ironically, pushing that small country – which is home to a major US military base — closer to Iran and Turkey. The US is also widening transatlantic divisions. Washington’s European partners will be eager to work with a newly re-elected Iranian President Hassan Rouhani and his foreign minister, Mohammad Javad Zarif, to try to stabilize the region. So long as the International Atomic Energy Agency continues to certify  that Iran is living up to its end of the nuclear deal, Europe will look for other avenues to deepen ties with the Rouhani government. Expect the Iranian leadership to capitalize on the growing rift between Washington and Brussels.

The irony for Tehran and Washington is that both sides need each other. Rouhani has promised the Iranian electorate that he will move on removing secondary sanctions imposed by Washington that hamper Iran’s integration into the global economy, while Trump has promised to bring peace and security to Washington’s Arab partners and to put an end to the Arab-Israeli conflict. None of these promises can be realized without Iranian buy-in or at least non-interference.

Amir Handjani is a nonresident senior fellow with the Atlantic Council’s South Asia Center and a member of the Atlantic Council Board. A Truman National Security fellow, he focuses on Iran-US relations, the Iran nuclear deal, the Persian Gulf, and Middle East security more broadly.