As Yemen sinks deeper into chaos, just whose wars are we fighting in the Middle East?

The air strikes launched by Saudi Arabian planes against Houthi rebel positions in Yemen may represent a significant escalation in the country’s increasingly bitter civil war. But the most significant damage caused by Riyadh’s surprise military intervention could concern the fate of the Obama administration’s delicate negotiations with Iran over the future of its nuclear programme.

The Saudis’ decision to come to the aid of Yemen’s beleaguered president, Abd-Rabbu Mansour Hadi, is in retaliation for Iran’s mounting support for the Houthi rebels, which earlier this month saw Tehran ship an estimated 185,000 tons of weapons to anti-government forces. Iran, the region’s Shia superpower, regards supporting the Houthis, a minority Shia group in Yemen, as a useful means of targeting Saudi Arabia’s conservative Sunni ruling family.

^{Shiite Houthi rebels in Yemen have attacked the presidential palace (Hani Mohammed/AP)}

To this end, the elite Quds force of Iran’s Revolutionary Guards has been providing weapons and other military support to the rebels for the past four years, helping the Houthis to overrun large swathes of the country, including the capital Sana’a, which was captured earlier this year. For decades the Saudis have regarded Yemen’s Sunni-dominated government as a loyal ally in their long-standing rivalry with Tehran, a dispute that has escalated alarmingly as a result of claims that Iran is attempting to acquire nuclear weapons.

Iranian attempts to wage a proxy war in the Saudis’ backyard have resulted in a number of recent rebel successes, to the extent that the entire country is now in danger of falling under Houthi control, with all the implications that would have for Saudi Arabia’s security.

The Saudis will argue that, with President Hadi being forced to flee from his makeshift refuge in the former British colonial port of Aden, they had no alternative but to intervene to save the country from falling victim to their bitter Shia rivals. Nevertheless, the fallout from their actions is likely to be felt far beyond the confines of the Houthi positions in Sana’a that were on the receiving end of the Saudi-led air strikes.

For not only have the air strikes plunged the region into an openly sectarian Shia-Sunni regional war, with an estimated 10 Sunni states supporting the Saudi offensive to prevent Yemen from becoming a Shia client state of Iran. Saudi Arabia’s military intervention could also have serious repercussions for Washington’s attempts to conclude a ground-breaking peace deal with Iran over its nuclear programme by the end of this month, particularly as Tehran is now accusing the US of orchestrating the Saudi offensive in Yemen.

Houthi fighters ride a patrol truck in Sanaa (Photo: REUTERS/Khaled Abdullah)

“America, which leads the fire mongering in the region, has supported this act,” announced Alaeddin Boroujerdi, the head of the Iranian parliament’s national security and foreign policy committee. “Saudi Arabia would not get involved without America’s permission.”

In the Swiss resort of Lausanne, where talks resumed yesterday morning between John Kerry, the US Secretary of State, and his Iranian opposite number, Mohammad Javad Zarif, on the nuclear issue, there was confirmation that the dramatic escalation of the fighting in Yemen could have a negative impact on the discussions, with the Iranian delegation demanding that Mr Kerry use his influence to prevent the outbreak of an all-out Arab-Iranian conflict.

Any tensions that develop between the two negotiating teams over the Yemen crisis will play into the hands of the hardliners in Tehran, who are already voicing their opposition to any deal with Washington, claiming that Mr Zarif is walking into a carefully laid American trap.

^{US Secretary of State John Kerry with Iran's foreign minister, Mohammad Javad Zarif (Ronald Zak/AFP/Getty Images)}

Strains between moderates and hardline defenders of the Islamic revolution are nothing new in Iran, and have hindered numerous Western attempts to mend relations with the ayatollahs over the past three decades. During the Eighties, efforts to negotiate the release of Western hostages, such as Terry Waite and John McCarthy, were stymied by the refusal of Ayatollah Ruhollah Khomeini, the Iranian revolution’s founding father, to countenance making a deal with a country he dubbed “the Great Satan”.

Similar attempts at a rapprochement during the Nineties following the election of the reformist Mohammad Khatami as president failed because his efforts were constantly undermined by hardliners in the Revolutionary Guards.

Now, despite claims made last weekend by Hassan Rouhani, the current leader, that the outlines of a deal with Washington might be possible by the end of this month, conservatives in parliament are already lining up to denounce their government’s efforts to resolve the issue once and for all, thereby paving the wave for the West’s punitive economic sanctions to be lifted. One prominent member of the majlis accused the government of accepting Washington’s claim that Iran’s nuclear programme is not designed for peaceful purposes.

The irony is that, were it not for the dramatic escalation in the Yemeni conflict, the deepening level of cooperation between Iran and the US in other parts of the Arab world would be sufficient to prove the hardliners’ concerns were groundless. For example, about 1,500 miles further north from the fighting in Yemen, the US-led coalition is actively supporting attempts by Iranian-backed Shia militias to recapture the strategically important city of Tikrit, Saddam Hussein’s former stronghold, which was seized by Sunni extremists fighting for Islamic State last summer.

As Iranian-backed paramilitaries continued their ground offensive, US planes have bombed key targets, forcing Isil fighters to withdraw, and raising the prospect that pro-government forces will soon succeed in reclaiming control of their first major Iraqi city from Sunni insurgents.

^{Shi'ite fighters launch rockets during a clash with Islamic State (REUTERS/Thaier Al-Sudani)}

Apart from forging closer cooperation on the battlefield, there are other indications that the Obama administration is keen to develop a more constructive relationship with Tehran. The publication of Washington’s annual National Intelligence Estimate this month, which lists the numerous threats America faces around the globe, makes no mention of either Iran or Hizbollah, the Iranian-backed Shia militia in southern Lebanon that has provoked frequent clashes with Israel.

For many years both have featured prominently on the list, but this year they have been quietly dropped in the hope that this gesture will persuade Tehran that the Obama administration is serious about resolving the nuclear issue by peaceful means.

Now there is a real risk that carefully laid groundwork with Tehran could be undone as a result of the fighting in Yemen, a conflict that has been provoked, to a large extent, by Iran’s unwelcome meddling in the Arabian peninsula.

For the truth of the matter is that, no matter how much the Obama administration would like to put its relations with Iran on a more even footing, Iranian interests in the Middle East are in direct conflict with those of the West, whether it concerns the development of nuclear weapons of the fate of failed or failing states like Yemen.

The rift in Islam

The split between Sunnis and Shias begins with the death of the prophet Mohammed in 632 AD, and the battle to succeed him as the first Muslim caliph. Sunnis say his brother-in-law Abu Bakr was the rightful heir; Shias say it should have been his cousin and son-in-law, Ali. It came to a head at the Battle of Karbala in modern-day Iraq in 680 AD with the death of Ali’s son Hussein at the hands of the Sunni army – an event which is still commemorated today.

Sunnis are the largest group, comprising around 85 per cent of Muslims and spread across the Islamic world from Pakistan to North Africa. Shias are a minority in most places – they were persecuted under the caliphs and the Ottomans – but hold power in Iran, where theirs is the state religion, and Iraq, where they form around two thirds of the population. The conflict has ebbed and flowed for centuries now; it won’t end soon.