The WOT involved direct and indirect forms of militarized interventions around the world. Wars in Afghanistan, Iraq and Syria were major fronts in the GWOT. The hunt for al- Qaeda and the war against the Taliban in Afghanistan, the 2003 invasion of Iraq and the wars against ISIS in Iraq and Syria all took centre stage at different points in time. The invasions and subsequent occupations of Afghanistan and Iraq entailed regime change, significant commitment of “boots on the ground” in long- term counterinsurgent wars and substantial nation- and state- building. Later interventions into Syria from 2014 primarily centred on aerial bombing campaigns against ISIS targets and the commitment of troops in an “advise and assist” capacity to regional armed groups allied to the US.

In addition, the US engaged in indirect forms of military intervention by supporting counterinsurgency and stability operations in various allied countries. From the Philippines to Colombia and the Sahel region of Africa, the GWOT prompted US engagement with allied governments and local partners towards US- led counterterrorism initiatives and “foreign internal defence”. As we explore in Chapter 5 , this “by, with and through” strategy, as it was known, also underpinned even more “remote” approaches to counterterrorist warfare that came to define the latter phases of the GWOT.

As discussed in Chapter 2 , jihadist Islamist movements posed serious political problems in various countries across the Middle East and South Asia. The GWOT was not just a series of transnational counterterrorism initiatives; it led to US military engagement in localized conflicts, active participation in stability operations and considerable state- and nation- building efforts, particularly in Afghanistan and Iraq. Where jihadist movements fuelled violent insurgencies, the GWOT compelled the US to develop and implement strategies and practices of counterinsurgency.

As its own phenomenon (distinct from, but related to, counterter-rorism), counterinsurgency can be defined as a set of politico military strategies combining military, political, economic and psychologi-cal operations aimed at undermining local insurgent movements. In such multifaceted engagements, “winning hearts and minds” and building stable, democratic societies were understood to be as impor-tant as defeating enemy combatants. Counterinsurgency operations not only involved “boots on the ground” engaged in combat but also efforts in infrastructure development, governance and humanitarian aid.