Israel and Iran appear to be on a collision course towards a war that would be terrible for both countries and the wider region. Such a conflict could draw in Iranian-allied fighters in Syria, Lebanon and Iraq – and possibly even Palestinians – to attack Israel from multiple directions.

It’s vital that the U.S. starts de-escalating the current tension between Israel and Iran to prevent this scenario from becoming a reality.

The Trump administration needs a comprehensive approach, which, detailed below, should include: Establishing red lines with Iran on actions we will not tolerate; opening a direct channel between the Trump administration and Iranian government; increasing efforts to contain Iran’s military presence in Syria; and preserving the Iran nuclear deal.

Iran is now believed to have as many as 10 military bases in Syria, including two near Israel’s border in the Golan Heights, as well as influence over a proxy force of roughly 20,000 fighters from various militias.

Israel is now taking action to prevent Iran from establishing a permanent military foothold in Syria.

When I worked on the Syria conflict for the U.S. State Department from 2012 to 2014, we often heard about Syrian fighters burying caches of weapons. In a line that sounded like something out of “Game of Thrones,” we heard that they were saving the weapons for the “war to come.” Some analysts believe that for Iran’s proxy fighters that future war may be against Israel.

In February, Iran directly entered Israeli airspace for the first time, using an armed drone capable of carrying four precision-guided bombs. It was an unusually aggressive move. Normally Iran uses proxy groups such as Hezbollah to threaten Israel, rather than risk a direct confrontation.

Israeli forces intercepted the drone and tracked its point of origin back to the Iranian-controlled Tiyas airbase in Syria, also known as the T-4 airbase. The Israelis then launched two waves of strikes against 12 Iranian-connected sites in Syria, in one of the Israeli air force’s most significant operations since the Lebanon War. An Israeli F-16 fighter jet was hit by a Syrian anti-aircraft missile, but the pilots managed to eject and land safely back in Israel.

Israel struck Syria’s T-4 base again on April 9, killing seven Iranians, and launched more attacks on April 29, killing 18 Iranians. Throughout Syria’s seven-year-long civil war, Israel has frequently used military force to prevent weapons transfers to Hezbollah, a long-established red line for the Jewish state.

These new attacks represent an escalation. Israel is now taking action to prevent Iran from establishing a permanent military foothold in Syria.

As Iran vowed retribution, the Israeli parliament voted to expand Prime Minister Benjamin Netanyahu’s war powers. American officials have reported that Israel has asked for help in the event of a war with Iran.

Israeli officials have also been telling U.S. and Russian officials that if Iran does retaliate for the recent strikes, Israel will go beyond Syria and attack Iran directly. No one knows how far the fighting would escalate after that.

This is why it is essential that the Trump administration de-escalate tensions between Israel and Iran. Here’s a fuller explanation of the kind of comprehensive approach the administration should be pursuing:

First, make sure Iran understands exactly what America will not tolerate. President Trump prides himself on being unpredictable, but in this case clarity may be the key to avoiding war. And doing so in concert with our allies would offer a show of force that would send a strong message to Tehran. President Trump’s recent meetings with French President Emmanuel Macron and German Chancellor Angela Merkel were missed opportunities to present this kind of united front.

Second, open an effective diplomatic channel with Iran to make sure the message gets through and that there’s a way to avoid dangerous misunderstandings. When I worked at the State Department, I saw how Secretary of State John Kerry’s relationship with Iranian Foreign Minister Javad Zarif helped diffuse tensions on a wide array of issues. Secretary of State Mike Pompeo is unlikely to build the same rapport, but he needs an open line to Tehran.

Third, do more to contain Iran’s presence in Syria, especially in the Golan Heights. This would help reassure Israel and prevent Iran from strengthening its threatening position on Israel’s border.

Unfortunately, President Trump is currently contemplating going in the opposite direction. He has said he wants to leave Syria “very soon” and “let other people take care” of the crisis in Syria. Meanwhile, National Security Adviser John Bolton has floated the idea of replacing the U.S. presence in Syria with an Arab military force. These approaches would effectively leave Israel alone to police its border.

The Trump administration is also shifting U.S. intelligence assets currently focused on ISIS away from Syria to Afghanistan. Instead, it should redeploy those assets to help Israel monitor Iranian movements in Syria, especially on the Golan Heights.

Fourth, to avoid inflaming the situation further, remain part of the 2015 agreement that put a lid on Iran’s nuclear program. Ripping up the deal – as President Trump is widely expected to do this week – would damage American credibility, empower hard-liners in Iran to restart their march toward a nuclear bomb, and make it harder to ever reach a new agreement to rein in Iran’s ballistic missile program, which is a threat to Israel.

The U.S. should instead be focusing on a follow-on deal that would offer additional sanctions relief to Iran in exchange for concrete concessions on ballistic missiles and counter-terrorism efforts.

There is no quick fix to preventing a direct war between Israel and Iran, but it is essential that the Trump administration start lowering tensions as soon as possible. A war between Israel and Iran would be catastrophic for the region. Avoiding it should be a top priority.