This briefing outlines why long-term strategies are a fundamental component of national climate policy architecture, and how SIDS can benefit from developing one, both directly in terms of prioritising efforts for achieving the Paris Agreement goals, and indirectly through synergies with other sustainable development and resilience goals. While focus here on the energy sector – the largest source of emissions for SIDS – an effective LTS should consider all sectors, as well as the interlinkages between them.