[1][2] Al-Naasan studied locally at Taybat al-Imam before graduating as an officer with distinction from a military academy, he assumed leadership positions in infantry and armored units of the Syrian Arab Army.

[2] After the Fall of the Assad regime, al-Naasan was appointed as Chief of the General Staff (COGS) and tasked with rebuilding the Syrian Army.

Al Jazeera in January 2025 reported that al-Naasan had "modernised" armament systems, introduced modern training and operational technology, and instituted an 'advanced training program' (برامج تدريب متقدمة) for officers and soldiers in crisis management and modern warfare.

[2] On 29 December 2024, Ahmed al-Sharaa announced the promotion of COGS Ali Noureddine al-Naasan to the rank of Major-General, together with the elevation of 48 other individuals including transitional Defence Minister Murhaf Abu Qasra, who was also promoted to the rank of Major General alongside al-Naasan.

[1][3] On 9 January 2025, al-Naasan's appointment as Chief of the General Staff was confirmed, according to Al Jazeera.