海角大神

If President Donald Trump arrived too late to serve as best man at the Saudi-UAE marriage of regional hegemons, he was definitely a close friend of the family: The Gulf Arab allies have played an important role in his campaign against Iran.

But after years of waging battle to drive Iranian influence from the Gulf, Saudi Arabia and the United Arab Emirates are now backing opposing sides in Yemen, as that country鈥檚 calamitous civil war, frequently cast as a major Saudi misadventure, refractures along decades-old dividing lines.

The split comes as the White House鈥檚 shifting policies and wavering support for Riyadh鈥檚 and Abu Dhabi鈥檚 regional ventures are bringing the two Arab allies鈥� differing views on how to counter Iran to the forefront.

And President Trump himself, whose ties to Saudi Crown Prince Mohammed bin Salman are becoming problematic for United States allies in the region, is increasingly playing the part of homewrecker, raising questions about whether the Arab world鈥檚 top power couple is heading toward divorce.

But their most pressing point of conflict is in Yemen.

This week, the UAE-backed Southern Transitional Council 鈥� separatists who demand an independent southern Yemen 鈥� overran forces loyal to the Saudi-backed government of Abed Rabbo Mansour Hadi. The STC seized Aden, Yemen鈥檚 second city and de facto capital of the Hadi government.

The development not only threatened to fragment Yemen anew, but it has also squelched Saudi hopes to restore Mr. Hadi鈥檚 control over Yemen and drive Iran-backed Houthis out of the capital, Sanaa.

The seizure of Aden was especially incendiary as it happened while Saudi Arabia was attempting to unify Yemeni factions at a summit in Riyadh. Not only was the move met with silence by the STC鈥檚 patrons, the UAE, but Abu Dhabi has also encouraged the STC to maintain control.

War of words

The public spat between the partners quickly became nasty, and revealing.

On Tuesday, from Riyadh, Mr. Hadi publicly blasted the UAE for backing the southern separatists, accusing the UAE in a separate letter to the United Nations Security Council of pursuing a 鈥渇ragmentation鈥� of Yemen through arming the group.

In Saudi Arabia, where everything Yemen-related is vetted by the palace, and the Yemeni government-in-exile is closely managed, it is widely thought that Mr. Hadi was also speaking for Saudi leadership.

鈥淗adi is reflecting the Saudi point of view of the UAE鈥檚 behavior in Yemen,鈥� says Imad K. Harb, director of research and analysis at the Arab Center Washington DC. 鈥淔or the Yemeni government to say the Emiratis are not doing the right thing in southern Yemen, that is a sign that the Saudis are not satisfied with their actions.鈥�

In the UAE,听commentators close to the ruling families responded by declaring the Saudi-backed Yemeni government ungrateful, corrupt, and a failure, insisting that Yemen will 鈥渂e difficult to reunite after today.鈥�

Other Emiratis started a social media campaign with the Arabic hashtag #Return_our_brave_soldiers_home.

The fact that both the UAE and Saudi Arabia employ an army of Twitter bots and script social media influencers and personalities to post talking points elevates the social media war to a state-level spat.

Iran

The Yemen tensions come in part from fundamentally different philosophies on how to counter Iran.

While Saudi Arabia sees a zero-sum game where its security can be guaranteed听only by regime change in Tehran, the UAE, which is just miles from Iran and would be the hardest hit by any military conflict, seeks merely to contain and push back Iranian influence in the Arab world.

For the past two years, their common distrust of Iran, shared by the U.S. president, was enough to paper over these differences. But as American military strikes on Iran this summer first appeared more likely and then were called off, Abu Dhabi and Riyadh began to drift.

In July,听an Emirati military delegation traveled to Tehran to discuss maritime security to听defuse Gulf tensions.

Unlike the U.S. and Saudi Arabia, when a tanker suffered an explosion off its shores in June, Abu Dhabi refused to publicly implicate Iran. Even the UAE鈥檚 language toward Iran has changed.

While Abu Dhabi is keen to act as a counterweight to Tehran, it wishes to avoid conflict as it听relies on its financial and maritime commerce for much of its wealth.听It听sees conflict as bad for business, and bad for stability.听And as recently as 2017, Dubai and Iran did $17 billion in trade.

鈥淒ubai factors in the UAE鈥檚 approach to Iran very heavily,鈥� says Giorgio Cafiero, director of the U.S.-based Gulf State Analytics. 鈥淚f the Iranians started firing missiles anywhere near Dubai, many American and European expats would leave immediately, and that would have devastating effects on Dubai鈥檚 financial and commercial sectors.鈥�

Saudi Arabia, which shares a 1,100-mile border with Yemen, saw the presence of Iran-aligned Houthis in control of the capital of its neighbor as an immediate threat to its security.

The UAE鈥檚 priority, however, was to prevent Iranian proxies from controlling the port of Aden and听the vital听shipping routes听from the Persian Gulf听to the Suez Canal.

With the听Hadi听government unable to regain control of Yemen, the Emiratis concluded that the next best scenario would be having the STC, the most powerful group in southern Yemen, look after听their听interests.

鈥淎lthough the UAE does not want Yemen to fall apart, they are OK with a semi-state in the south that would protect their maritime interests,鈥� says Mr. Harb of the Arab Center Washington DC.

Trump

But perhaps nothing is driving the wedge between Saudi Arabia and the UAE more than the behavior of the Trump administration itself.

After agreeing to billions in business deals with Washington, the UAE bought into the Saudi crown prince鈥檚听playbook: work closely听and directly听with President Trump in return for U.S. support and protection for Gulf projects and wars across the region.

In recent months that sure thing has turned into a bad bet: President Trump has called off military strikes on Iran; done a reversal and embraced their rival, Qatar; and soured on Gulf interference in Sudan and Libya.

Even more worrying is the politicization of the Gulf鈥檚 relationship with Washington; those close to the leadership in the Emirates say they are aware that the closer they are aligned with the U.S. president,听the more vulnerable they would be to any political setbacks to him.听

And听with Saudi听Arabia鈥檚听brand becoming toxic听following the killing of journalist Jamal Khashoggi, the UAE听is working quietly to publicly distance itself from the crown prince in the West.

鈥淭he UAE鈥檚 interest is avoiding the kind of reputational damage that Saudi Arabia has suffered in Washington and London as a consequence to the Khashoggi killing and the Yemeni civil war,鈥� says Mr. Cafiero, the analyst.