How does a military organization define its ability to wage war, and how do such definitions evolve over time? This study investigates the concept of warfare capability (krigföringsförmåga) in Swedish military strategic doctrine, using a conceptual historical approach grounded in Reinhart Koselleck’s theory. Through an analysis of Swedish strategic doctrines from 2002 to 2022, the study traces how the concept has shifted from an emphasis on operational resources and tactical employment to a more strategic, dynamic, and future oriented understanding. Initially defined in terms of available means and their effective application in combat, the concept gradually came to encompass adaptability, anticipation of future threats, and military credibility. The study contributes to doctrine development research by illustrating how core military concepts are historically shaped. For practitioners, the findings highlight the importance of critically engaging with doctrinal language as tools that must be continuously interpreted, questioned, and adapted to meet evolving strategic challenges.