War in History is the most important journal dealing with strategic studies that also carries a historical dimension.
Journal of Strategic Studies is a valuable reference in strategic studies.
Small Wars and Insurgencies concentrates especially on insurgencies and counterinsurgency; the main debates are covered here.
RUSI Journal is published by the Royal United Services Institute, and gives current debates on the theory and practice of strategy.
For the US Army see the Military Review.
For the US interservice debate, see Joint Force Quarterly published by the US National Defense University.
Res militaris is a bilingual (English, French), peer-reviewed, on-line social science journal dedicated to the study of military- and security-related issues, broadly defined.
British Journal for Military History is a peer-reviewed online journal which devotes a section to the practice of strategy.