It’s been in the works since 2016, and dubbed a ‘comprehensive strategic partnership’. The deal signed between China and Iran is expected to boost their long-standing economic and political alliance. The cooperation will cover a wide range of Chinese investments in Iran’s most important sectors, including energy and infrastructure. It’s the first long-term agreement of its type to be signed by Iran with a major world power. And comes at a tough time for Iran’s economy that’s been devastated by U.S. sanctions. What do both countries stand to gain? And should people be worried, in the Middle East and beyond?