The relationship between Syria and Iraq resists simple classification within conventional models of regional systems, yet it stands as one of the defining features of the Arab Levant’s modern history. This unique and enduring bond cannot be explained solely through the lens of ancient sectarian or theological divisions. To reduce it to historical rivalries—such as those between the Umayyads and Hashemites, or Sunni and Shia factions—is to perpetuate a flawed narrative of perpetual sectarian conflict.
Instead, the foundation of the Syria–Iraq relationship lies in the emergence of modern political entities following the post-First World War partitioning of the Ottoman Empire under the 1916 Sykes–Picot Agreement and its 1920 amendments, which transferred Mosul from French-administered Syria to British-controlled Iraq.
A Shared Historical Trajectory
The modern bond between Syria and Iraq began to form with the establishment of these two states. After the French expelled King Faisal I from Damascus in 1920, the British offered him the Iraqi throne, a position initially desired by his brother, Abdullah, who was eventually persuaded to rule over Transjordan. Despite this rearrangement, the Hashemites did not relinquish their ambitions in Syria. Iraq’s regent, Abdul Ilah, championed the “Fertile Crescent” project, while Jordan’s King Abdullah envisioned a “Greater Syria” until his assassination in Jerusalem in 1951.
The 1930 Anglo-Iraqi Treaty, which secured Iraqi independence and membership in the League of Nations, became a model for Syrian leaders seeking similar status from the French mandate. As Patrick Seale notes in The Struggle for Syria, Iraq even financed the Syrian delegation—led by Hashim al-Atassi—sent to negotiate the 1936 Franco-Syrian Treaty in Paris. In 1941, Iraq’s Prime Minister Rashid Ali al-Gailani launched a rebellion against British dominance, which garnered considerable Syrian support, especially due to his calls for the liberation of Syria and Lebanon from French control.
Iraq played a pivotal role in Syria’s political landscape throughout the 1940s and 1950s. It supported Sami al-Hinnawi’s 1949 coup, which aligned with Aleppo’s People’s Party and its push for union with Iraq. Baghdad also competed with Cairo for influence in Damascus, seeking to draw Syria into the pro-Western Baghdad Pact. In response to Syria’s 1958 union with Egypt under the United Arab Republic (UAR), Iraq’s military attempted to topple its monarchy, hoping to join the UAR itself.
The Ba’ath Party—founded in Syria—took power in Iraq on 8 February 1963 and in Syria a month later. When Syria’s Ba’ath leadership was deposed in a 1966 coup, party co-founder Michel Aflaq sought refuge in Iraq, where he remained until his death in the late 1980s. For over 25 years, the rival Ba’athist regimes in Damascus and Baghdad vied for ideological supremacy and Arab leadership.
Parallel Paths in Crisis
The fall of Iraq’s Ba’athist regime in 2003, following the US-led invasion, foreshadowed the eventual collapse of Syria’s Ba’athist state in December 2024. The fates of the two nations became even more entwined during the Syrian uprising. The Islamic State of Iraq (ISI) established its Syrian affiliate, Jabhat al-Nusra, which later evolved into Hayat Tahrir al-Sham (HTS)—now in control of Damascus. Meanwhile, ISIS, having emerged from Syria’s Raqqa, captured Mosul and large parts of western Iraq in 2014, declaring a “caliphate” and effectively erasing the border between the two states.
In his first televised address as leader in Damascus, HTS chief Ahmad al-Sharaa cited his experience in Iraq from 2005 to 2011, pledging to avoid the sectarian strife that devastated Iraq. His remarks underscored the striking symmetry between the two nations—where the present of one frequently mirrors the future of the other. As al-Sharaa acknowledged, each country serves as a distorted reflection of the other’s trajectory, with their political and security fates tightly interwoven.
Strategic and Regional Implications
The Syria–Iraq nexus functions as a self-regulating axis of power within the Arab Levant, shaped by colonial legacies, nationalist projects and ideological movements—from pan-Arabism and Ba’athism to the rise of jihadist insurgencies. Their shared border, complex demographic compositions and geostrategic significance have made both countries battlegrounds for regional and international rivalries—from the Cold War’s Baghdad Pact era to 21st-century tensions between the United States and Iran.
The 2003 invasion of Iraq triggered profound regional instability, empowering non-state actors such as ISIS. The reverberations of its rise—and eventual territorial defeat—continue to shape dynamics in both Iraq and Syria. Likewise, Syria’s current transitional phase under HTS is likely to impact Iraq’s fragile equilibrium, particularly as both nations struggle to integrate diverse communities and fend off foreign meddling.
A Symbiotic Relationship
The deep-rooted historical and political entanglement between Syria and Iraq underscores their position as twin pillars of the Levant’s geopolitical order. Their destinies are not simply parallel but symbiotic—each shaping, influencing and reflecting the other’s trajectory. From monarchy to revolution, from Ba’athist rule to insurgency and reconstruction, the story of one cannot be fully understood without the other.
As Syria charts its uncertain path forward, Iraq’s stability may well depend on it—and vice versa. In the Levant, the fates of Damascus and Baghdad remain inextricably linked.