Carriers and submarines cannot replace a combined force

How should the cost of a Challenger 3 tank turret be weighed against the number of basic houses the same money might build?

Both needs remain real, and the tank only delivers military value as one part of a supported combined-arms force rather than as a solitary war-winning platform.

Military platforms succeed as parts of a coordinated force rather than as solitary war-winning machines. Tanks need reconnaissance, artillery, air support, and infantry. The same warning applies to claims that submarines alone can win a war or that an aircraft carrier fights independently of its task group. Equipment creates options, while deployment and mutual support determine whether those options can be used. A capable platform can still become vulnerable when terrain and formation prevent it from fighting as intended. Force structure and doctrine matter as much as the performance of the headline ship or weapon.