Turkish president Recep Tayyip Erdogan has become the key external actor in Syria following the sudden fall of Syria president Bashar al-Assad and the Baath party. He secured supremacy by backing al-Qaeda's defected offshoot Hay’at Tahrir al-Sham (HTS) and the merger of armed opposition groups into the Syrian National Army (SNA).

To assert his claim to credit, Erdogan dispatched intelligence chief Ibrahim Kalin to Damascus to confer with HTS leader Ahmed al-Sharaa, who is known by his nom de guerre Abu Mohammed al Golani, and the head of Syria’s transitional government Mohammed al-Bashir.

After opposition factions seized control of Syria's northwestern Idlib province, Ankara armed and protected them. During the past year, Turkey prepared them to mount the surprise 11-day campaign which toppled the 54-year-old Assad regime. This became Erdogan's longstanding goal because Assad refused to cede to his demands.

Erdogan began issuing these demands in 2009 by calling for Assad to amend the Syrian constitution which enshrines secularism as the foundation of governance and permit the Muslim Brotherhood to enter political life. After unrest erupted in 2011, Erdogan recruited defected Syrian army officers and men to form the Syrian National Army and backed the establishment by Syrian expatriates of the Syrian National Council which was based in Istanbul. Erdogan was joined by Western powers to press the Assad government to negotiate on transition to a new government which would share power with the Muslim Brotherhood-dominated expatriate opposition.

Erdogan is set to pursue three political objectives now that Assad is gone. First, he claims he will stabilise Syria by securing a political solution in accordance with United Nations Security Council resolution 2254 of 2015. This calls for the formation of an inclusive interim government which would conduct elections permitting Syrians to choose their rulers. Erdogan is counting on HTS to manage not only the transition but also the election.

Second, Erdogan is determined to repatriate most of the 2.9 million Syrian refugees living in Turkey since they have become unpopular with many Turks. He is blamed for welcoming them early in the Syrian civil conflict and for backing the armed and political opposition battle against Assad which has prolonged the refugees stay in Turkey.

Third, Erdogan is determined to contain the US-supported Kurdish-led Syrian Democratic Forces (SDF) militia which has established an autonomous region in the northeast that covers 25 per cent of Syrian territory. He regards the SDF as a “terrorist” partner of Turkey's Kurdish Workers party (PKK) which has been fighting Ankara off-and-on since 1978. Tackling the SDF is tricky because it is protected by 900 US troops and US air power. Washington came to rely on the SDF, the most effective local fighting force, during the 2017-2019 campaign against Daesh in Syria and Iraq.

Turkey's ailing economy could benefit as Ankara's ties to HTS could enable Turkish firms to receive preferential treatment once Syria begins reconstructing war-ravaged cities, towns and villages and infrastructure. Turkish exports of food, fuel, and other supplies could flourish immediately and once stability is restored.

While Turkey has gained political and military influence in Syria as well as a boost in its regional status, Iran has suffered dramatic losses from Assad's fall. Tehran was Damascus' closest ally and Syria was the sole state in the Iran-founded "Axis of Resistance" to Israel and the US which included Palestine's Hamas, Lebanon's Hizbollah, and Yemen's Houthis.

However, before Assad was ousted, the membership of axis had been reduced to Yemen. Israel had crushed Hamas in Gaza and crippled Hizbollah in Lebanon. This dramatically reduced Iran's politico-military regional outreach.

While Damascus had normal diplomatic relations with the pro-Israel US-backed regime in Tehran, Syria and Iran developed close strategic ties after Iran’s 1979 clerical revolution toppled the shah. Due to feuding between rival branches of the Baath party in Iraq and Syria, the latter supported Iran during the 1980-1988 war. Gulf states armed I And funded Iraq. As Baghdad had widespread Arab political support, by option for Iran Syria endured decades of Arab ostracism which endured during the Syrian civil/proxy conflict and ended only in 2023.

After Egypt's 1979 peace treaty with Israel deprived the Arab world with military muscle to fight Israel, Iran fostered the "Axis of Resistance" to stand against Israel and the US. Following Israel's 1982 invasion of Lebanon, Iran forged Hizbollah from diverse Shia factions. Iran also trained and armed Hamas fighters and provided the Houthis with weapons.

Before Assad’s ouster, Iran's Revolutionary Guards Quds force provided the Syrian army with advice, logistical support, arms and ground forces while Russia supplied weapons and air cover. Armed opposition factions were driven from around Damascus, Homs and Hama, and eastern Aleppo and confined to Syria’s northwest Idlib province. As Idlib is Turkey’s neighbour, Erdogan was well positioned geographically to carry out his plan. Tehran’s role in Syria ended with the victory of HTS and its partners.

Iran's supreme guide Ayatollah Ali Khamenei has blamed Assad's fall on Israel, the US and a neighbour without naming Turkey. Although Khamenei was primarily responsible for Tehran’s Syria policy, officials in Tehran seek to avoid criticism by claiming they had predicted Assad's collapse due to his longstanding refusal to negotiate with the opposition. The loss of Syria comes at a time of trial and tribulation for Iran's clerical rulers who face a stressed economy, rising internal dissent, and the return to office in the US of Donald Trump in a month's time.

Trump has not so far commented on Iranian President Masoud Pezeshkian's call for the revival of the 2015 agreement lifting sanctions on Iran in exchange for limiting its nuclear programme. Trump withdrew from the deal in May 2018 and imposed 1,500 sanctions on Iran, crippling its economy.

Iran responded by breaching limits on uranium enrichment and stockpiles and reducing monitoring by the International Atomic Energy Organisation. If Trump dismisses Pezeshkian's initiative and sticks to his hardline policy of "maximum pressure," Iran could decide to opt for the nuclear weapon option to deter the US and others from attacking Iran in order to effect regime change.
Michael Jansen, Political Correspondent