Complex sentence: Finally, a third reason is the role of long-term air support for areas with a low threat level (Iraq, Afghanistan), the latter referred to as close air support for the global war on terror (CAS for GWOT).
Split into simpler sentences: Finally, a third reason was long-term air support for areas with a low threat level (Iraq, Afghanistan). The latter was referred to as close air support for the global war on terror (CAS for GWOT).