The Syria crisis continues to fuel the largest displacement crisis in the world. Ecological degradation and climate disruption are impacting and shaping the humanitarian and development operations that have been mounted in response. These include those under the umbrella of the Regional Refugee and Resilience Plan in Response to the Syria Crisis (hereafter known as the 3RP). 3RP countries – Egypt, Iraq, Jordan, Lebanon, and Türkiye – have been housing refugees of this crisis for over a decade. Together, they host a population of approximately 7.1 million refugees, asylum seekers, and stateless persons, as well as 12.9 million impacted host community members. The urgent development and humanitarian challenges triggered by the Syria crisis are exacerbated by an interlinked, but often less visible, slow- motion crisis: ecological degradation in the form of growing water insecurity, rising temperatures, decreasing agricultural production, and the legacies of the conflict. Even before the conflict erupted in 2011, the sub-region was considered the world’s most water scarce, and one where land and water resources were highly politically sensitive, both at a community level and across borders.