One of President Trump’s key goals has been to systematically reverse the policies of his predecessor. So it’s no surprise that Trump’s visit this weekend to Saudi Arabia, his first to a foreign country, will signal a break with Barack Obama’s foreign policy in the Middle East.

This is both promising and potentially troubling.

That Riyadh and Jerusalem are the first stops on this trip is clearly Trump’s attempt to distance himself from Obama’s rapprochement with Iran.

The previous administration’s calculation here involved creating a balance of power between the regional actors, namely Saudi Arabia and Iran, in order to diminish the US military footprint in the region. Obama’s strategy failed.

Trump, in contrast, has a strong desire to side forcefully with America’s traditional allies, Saudi Arabia and Israel, and has made a point of identifying Iran as the source of instability in the region.

Not incorrectly, he sees Iran as having used the cover of the nuclear agreement reached with six major powers in 2015 to increase its influence throughout the region, especially through the use of non-state actors such as Hezbollah in Lebanon and Syria, Houthi rebels in Yemen and the Popular Mobilization Units in Iraq.

Trump will be fêted in Riyadh for giving primacy to America’s strategic relationship with the kingdom, and will be hailed as a partner by moderate Muslim states such as Jordan and the United Arab Emirates in the war against extremist radical movements like Sunni Islamic State as well as Shiite Hezbollah.

Sunni jihadists, equally at war with Sunni states such as Saudi Arabia and Egypt, cannot be defeated without an alliance with the wider Sunni world. The Saudis have warded off several al Qaeda attacks against the homeland, and have allowed the US to use their territory as a base for attacks against al Qaeda and ISIS.

Trump will certainly acknowledge this, and is expected to give a major speech on Islam and the West, with hope of putting to rest his reputation as an Islamophobe.

In return, Saudi Arabia is likely to announce significant investments in infrastructure projects in America (perhaps as much as $40 billion) and that it will be buying $100 billion or more in US arms.

Emphasis will be placed on the two countries’ historic economic and political partnership — the summit’s slogan is “Together We Prevail.”

And since Jerusalem will be the next stop after Riyadh, it is rumored that Trump will obtain from the Saudis and their Gulf neighbors a major concession toward Israel in order to restart the Palestinian-Israeli peace process.

This might involve giving El Al, Israel’s national airline, overflight rights, or perhaps the establishment of direct telecommunication links.

It is no secret that the common enmity for Iran has brought the Gulf States and Israel closer, especially on security and intelligence, and Trump hopes to capitalize on this.

But for this to play out, Israel must immediately offer the Palestinians something tangible, such as permanent cessation of all settlement construction in the West Bank.

If not, Iran, Assad, Hezbollah and the Houthis will have a strong argument to the Muslim world that revanchism is the only avenue for dealing with Israel.

Another difficulty lies with how Trump will handle Iran. His former national security adviser, Gen. Michael Flynn, famously put Tehran “on notice” for testing a ballistic missile. But what does this mean in practice?

Yemen, Saudi Arabia’s soft underbelly, offers the best arena to begin to roll back Iranian influence. Tehran is clearly involved in supporting and supplying weapons to the Houthi rebels, attempting to create a Hezbollah-like force that can harass Saudi Arabia across the border.

This is what has provoked the Saudis to wage their controversial war there, and despite universal condemnation of civilian casualties, it will continue to do so until Iran’s plans are frustrated.

For Iran, by contrast, Yemen is not a strategic asset. It should be possible to make the regime understand that its foray in Yemen will come at a cost, say the sinking of any ship that is found carrying weapons to the Houthis, along with new sanctions.

Instead, opening up a dialog with Iran about Yemen, which would include Saudi Arabia and its allies, might start the process of de-escalation across the entire region.

Perhaps more importantly, it would also show that without America’s active engagement, the region will remain a boiling cauldron, and that Obama was wrong by adopting a hands-off policy.

Trump should like that.

Bernard Haykel is a professor of Near Eastern Studies at Princeton University.

© 2017, Bloomberg