Discuss the linkages between sectarian conflict and the emergence of non-state terrorist actors like ISIS in post-invasion Iraq.

The 2003 invasion dismantled Iraq's Ba'athist state without building an inclusive successor. The ensuing Shia-Sunni contest was not merely the backdrop to al-Qaeda in Iraq and its ISIS offspring — it was their principal enabling condition.

Sectarian conflict as the seedbed of terrorism

• De-Ba'athification and disbandment of the army stripped a largely Sunni officer class of status and livelihood, leaving a reservoir of trained, aggrieved recruits that al-Qaeda in Iraq absorbed.
• Security vacuum: by 2006 the UN Special Representative told the Security Council that Iraq stood on the brink of civil war, with "violence seems out of control" [1]. AQI deliberately attacked Shia shrines to provoke reprisals, converting terrorism into a self-sustaining cycle.
• Exclusionary governance: UN briefings in 2014 stressed that government reconciliation with marginalised communities was critical to fighting the common terrorist threat [2]. That alienation made Mosul and Anbar permissive terrain for ISIL's 2014 sweep.
• Militia counter-violence allowed ISIS to pose as a "protector" of Sunnis — a protection racket built on fear.

Sectarianism as ISIS's operating ideology

• Once entrenched, ISIS industrialised sectarian and ethno-religious persecution — of Yazidis, Christians and Shia Turkmen — prompting the Council to create a dedicated investigative team for crimes amounting to war crimes, crimes against humanity and genocide [3].
• Recovery remained hostage to the same fault line: the UN warned that liberation operations must avoid revenge attacks and steps inciting sectarian tension [4].

Regional proxy dimension

• Rival external patrons hardened the divide; UNAMI continues to flag armed actors operating outside State control [5], and sectarian militancy now feeds a wider regional confrontation the Council has repeatedly debated [6].

Post-invasion Iraq shows that terrorism grew less from ideology alone than from state collapse plus exclusion. Durable counter-terrorism therefore lies in inclusive federal power-sharing, a monopoly on legitimate force, and transitional justice — the institutional route that SDG-16 envisages, and the surest guarantee that Iraq's hard-won victory over ISIS is not reversed.