Here are a few options for a formal equivalent, depending on your preferred emphasis:
Option 1 (Concise and Academic):
Hybrid Threats and Nuclear Risks: An Assessment of the European Security Landscape
Option 2 (Slightly more authoritative):
Navigating Nuclear Risks Amidst Evolving Hybrid Threats in Europe and Beyond
Option 3 (Direct and Institutional):
The Intersection of Hybrid Threats and Nuclear Risks in Europe: An IISS Strategic Analysis
Recommendation:
Option 1 is the most standard format for international policy papers and think-tank reports.