International Institute for Strategic Studies

The International Institute for Strategic Studies (IISS) is an international research institute or think tank focusing on defence and security issues. Since 1997, its headquarters have been at Arundel House in London. It has offices on four continents, producing data and research on questions of defence, security and global affairs, publishing publications and online analysis, and convening major security summits. ''The Guardian'' newspaper has described the IISS as ‘one of the world’s leading security think tanks.’

The current Director-General and Chief Executive is Bastian Giegerich while Sir John Chipman is the Executive Chairman.

The 2017 Global Go To Think Tank Index ranked IISS as the tenth-best think tank worldwide and the second-best Defence and National Security think tank globally; Think Tank Alert ranked it as the top, most-cited non-US-based think tank in 2025; while Transparify ranked it third-largest UK think tank by expenditure, but gave it its lowest rating, describing it as deceptive, on funding transparency. Provided by Wikipedia