One of former President Barack Obama’s only achievements in his disastrous Middle East policy was to align two rivals together against a common threat. His love affair with Iran left Israel and other allies in the Arab world feeling undermined by the United States. Obama’s nonchalance toward the Iranian threat actually forced countries that had never gotten along to work together.

A great example of this is the informal budding relationship between Israel and Saudi Arabia — two important American allies. Saudi Arabia and Israel have never had diplomatic relations and for years have stood at odds with one another. Now, an emboldened Iran is the common enemy uniting them.

Iranian aggression is threatening the stability and security of the Middle East. Both Saudi Arabia and Israel have experienced this aggression in unique ways. In Yemen, Iran has backed Houthi rebels against the government. This has exacerbated a civil war with devastating effects on the civilian population. The Houthis also have Saudi Arabia in their sights, even firing Iranian-supplied missiles at the capital city Riyadh.

For years, Iran has backed terrorists groups such as Hamas and Hezbollah, which have worsened conflicts with Israel. In the Gaza Strip, Hamas regularly carries out attacks on Israel by using Iranian-funded weaponry. In Lebanon, Hezbollah broadcasts pro-Iranian propaganda, covertly builds underground bunkers under civilian houses, and has amassed an arsenal of rockets and missiles for its next war with Israel.

As a result, two long-standing historical enemies staged a rapprochement in the face of the Iranian threat. Iran is simultaneously a unifying threat. Israel and Saudi Arabia have reportedly shared intelligence, especially about Iran, for several years. Recently, the two are making their cooperation more public.

There has been informal engagement between officials of both countries, too. In 2015, a retired major general from the Saudi armed forces and a former Israeli ambassador shared the stage at the Council on Foreign Relations. The men acknowledged their countries’ relationships with the U.S. and expressed hope that this event would spark further discussion about their mutual problems.

Within the last year, both nations have made small steps toward a positive relationship. In May 2017, President Trump made history when he flew from Riyadh to Tel Aviv — reportedly the first direct flight between Saudi Arabia and Israel.

In November 2017, two former intelligence officials, one from Saudi Arabia and the other from Israel, sat on a panel together to discuss their respective countries’ mutual interests. That same month, during an unprecedented interview with a Saudi news organization, the chief of staff of the Israel Defense Force said that Israel is willing to exchange intelligence about Iran with Saudi Arabia.

One week after the interview, two Saudi officials visited a synagogue in Paris — a move that would have never happened without Riyadh’s approval.

Most recently, Saudi Arabia undid a 70-year ban that prevented flights bound for Israel from using Saudi airspace. The Kingdom announced that Air India would be able to fly directly to Tel Aviv across Saudi Arabia, making the route for Asia travelers more convenient.

Whether Saudi Arabia will allow Israeli airlines eventually to fly through Saudi airspace remains unknown. But the answer could potentially say something about the direction of their relationship.

The significance of this growing relationship cannot be understated. Saudi Arabia is home to two of the holiest sites in Islam. Sunni nations in particular look to them as the leader of the Muslim world.

At the same time, many of these nations, including Saudi Arabia, have not recognized Israel’s right to exist. Saudi Arabia’s public cooperation with Israel could inflame both the religious establishment in the region and the so-called Arab Street. The Saudi Arabian government’s willingness to risk its credibility with its people speaks volumes to how dangerous Iran is.

Despite the collaboration between the two countries, we shouldn’t be overly optimistic. The animosity between Israel and Saudi Arabia is rooted in strong historical and religious conflict, and that won’t disappear overnight.

Time will tell whether the relationship grows or simply fades into what could have been. Nevertheless, these recent events are promising.