Hizbollah fighters drive off from the Marjayoun barracks with a tank that belonged to Israel's local militia in south Lebanon on May 24, 2000. Reuters

Israel and Saudi Arabia don't have official relations and Riyadh still does not recognize Israel's right to exist. But the two states have held five secret meetings since the start of 2014 in order to discuss the rise of Iran, Eli Lake reports for Bloomberg View.

The meetings have led to a level of unprecedented strategic understanding between the two countries.

"We discovered we have the same problems and same challenges and some of the same answers," Shimon Shapira, a retired Israeli general and participant of the talks with Saudi Arabia, told Lake.

The Iranian nuclear deal and the threat of a rising Iran is uniting the two longstanding Middle Eastern opponents.

As Iran expands its influence throughout the region in Iraq, Syria, Lebanon, and Yemen, Saudi Arabia and Israel have found themselves increasingly united on a confluence of issues. Both countries are concerned over the proliferation of Iranian-backed militias throughout the region and the potential dangers of Iran acquiring a nuclear weapon.

Israel has repeatedly fought the Lebanon-based, Iran-backed militia Hezbollah, with which it fought a month-long war in 2006. Saudi Arabia, which launched a military operation in Yemen to push back Iranian-supported Houthi rebels who had deposed the country's recognized government, is also experiencing cross-border rocket attacks from the militia group. Sunni Saudi Arabia has also long competed with Shi'ite Iran for influence in the Middle East and throughout the Muslim world.

This has led to a certain degree of public sympathy from Saudi Arabia's leaders over Israel's strategic situation — something that might have been unthinkable until recently.

“Wherever the Iranians are present, they create militias against these countries,” Saudi military spokesman Brig. Gen. Ahmed al Aseeri told Yaroslav Trofimov of The Wall Street Journal. “In Lebanon they have created Hezbollah, which is blocking the political process and has conducted wars against Israelis, destroying Lebanon as a result. And in Yemen, they have created the Houthis.”

Houthi fighters stand near a damaged guard post at a Presidential Guards barracks they took over on a mountain overlooking the Presidential Palace in Sanaa January 20, 2015. Khaled Abdullah/Reuters Aside from Iranian paramilitary groups, the two countries, which do not have official diplomatic relations, are also concerned over the potential of an Iranian nuclear program. Israel has previously threatened to use military force against Iranian nuclear sites, while some within the Saudi security establishment may think that Riyadh could aid a potential Israeli strike, perhaps by allowing Israeli jets to refuel on Saudi territory.

"If I were a Saudi decision-maker, I would not hesitate for a second to coordinate with Israel against Iran’s nuclear program," former senior Saudi diplomat Abdullah al Shammari told the WSJ.

This willingness to work alongside Jerusalem reflects a growing perception within Saudi Arabia that Iran poses a greater threat than Israel. A recent poll within Saudi Arabia found that 53% of Saudis thought of Iran as their main adversary, compared to only 18% thinking the same of Israel.

An overwhelming 85% of Saudis also support the Saudi-led Arab Peace Initiative, according to the AP. This initiative would result in peace between Israel and every Arab country in exchange for a return to the country's pre-1967 borders and other conditions.