This chapter examines the evolution of agri-environmental policies in major developed countries, focusing on their role in promoting sustainable agricultural practices. It explores various policy measures, including regulatory approaches, economic incentives, and market-based mechanisms like conservation auctions and emissions trading, drawing on international examples. Special attention is given to the EU’s Common Agricultural Policy, North American policies, and innovative approaches in Australia and New Zealand. The chapter highlights the need for rigorous impact evaluations to improve policy effectiveness, despite challenges like uncertain costs and long timeframes for realizing effects. Future evaluations could use quasi-experimental methods combined with remote sensing. Spatial coordination incentives, offering payments for group cooperation among farmers, are also crucial. Additionally, innovative payment schemes, such as performance-based and auction-type payments, are being explored, with growing potential for private sector involvement. By contextualizing Japan's policies within global trends, the chapter emphasizes aligning with international sustainability goals while adapting to local conditions. It advocates for evidence-based approaches like payments for ecosystem services (PES) and integrating new technologies to optimize policy effectiveness, ultimately fostering a comprehensive dialogue for sustainable agricultural systems.