Contextual explanation: Supporter of Arab nationalist political movement. 
A Ba'athist is best understood as an individual or group aligned with the Ba'ath political movement, which advocates for Arab unity, nationalism, and state-led modernisation across the Arab world. Ba'athism has played a significant role in shaping political structures and ideologies in several Middle Eastern countries, most notably Syria and Iraq, by promoting a vision of pan-Arab identity and centralised governance.

Themes: Nationalism and political ideology. 
The concept of Ba'athist is closely tied to the theme of nationalism, as it centres on the unification and empowerment of Arab peoples under a shared political and cultural identity. It also embodies the broader theme of political ideology, reflecting a specific set of beliefs about governance, social order, and modernisation within the context of Arab societies.

Nuance: State-led modernisation and pan-Arab unity. 
What distinguishes Ba'athism within the politics category is its emphasis on state-driven modernisation and the pursuit of pan-Arab unity. Unlike other nationalist movements, Ba'athism combines socialist principles with a focus on secularism and centralised authority, aiming to transform society through both ideological and institutional reforms.