In any professional military, strategic planning is implemented for contingency plans in various theaters of war. You can have a competent army but simultaneously be caught off guard in combat if your contingencies need to be thoroughly implemented.
The United States, the strongest capable conventional military on Earth, has struggled with unconventional warfare, as nation-building in unstable countries in the Near East was nearly impossible. Today, it is crucial to differentiate a competent military from its contingencies because you can be a ‘great power’ per se but falter in the war due to poor contingency planning.
What is Capability?
In military terminology, a capability is the ability to achieve a desired effect under specific standards and conditions. The core function of a capability is to accomplish a wartime objective with as minor damage to your warfare capabilities as possible.
The Armed Forces of the United States are a textbook example of achieving military capabilities through superior air and naval capabilities. As a part of military science and intelligence, strategic planning amongst commanders attempts to find ways of defeating an enemy with existing or new concepts.
Post-WWII, the United States and its Western European allies attempted to find capabilities for the threat of conventional war with the Soviet Union, which had a near-endless pool of manpower, tanks, and artillery. NATO would incorporate the central strategy of air superiority, which the Soviet Union and modern-day Russia lacked the capabilities of.