Center for Security Studies, ETH Zurich http://www.css.ethz.ch/en/services.html contains a wealth of relevant information, including articles on geopolitics and grand strategy.

Exploring Geopolitics http://www.exploringgeopolitics.org/ is a rich resource on classical and contemporary geopolitics, with many interviews with leading academics in the field as well as introductory articles on relevant topics.

Foreign Policy magazine http://foreignpolicy.com analyses US foreign policy, often with an eye for geopolitical questions and discussions of US grand strategy.

Geopolitics and Security, blog run by the Geography department at RHUL, https://rhulgeopolitics.wordpress.com/ is a blog on current geopolitical themes, interpreted through the lens of critical geopolitics and in particular the ‘popular geopolitical culture’ approach by Klaus Dodds, professor at RHUL. It provides an expanded view of geopolitics as an interpretative frame to understand everything from fake news to the Arctic issue.