The six Duncan-class battleships were publicly justified as an answer to three fast Russian ships. That rationale does not fully explain the order because the Royal Navy already possessed a much wider global force and wanted additional 19-knot battleships for worldwide coverage. Six ships could help guarantee three available units while reinforcing an already formidable numerical margin. The resulting overmatch deterred battle by letting Britain concentrate locally, threaten elsewhere, and force an opponent either to mass defensively or risk defeat in detail.
Notable Point · 35:59-40:00
Duncans and deterrence through overmatch
The Duncan class reveals a fleet policy aimed at more than matching rivals: it sought enough ships to create credible overmatch worldwide.