Why Britain argued that it needed seventy cruisers

The Royal Navy approached treaty negotiations with a worldwide presence requirement that went beyond matching enemy battle fleets. The 4,180-ton HMS Calypso illustrates the problem: a C-class cruiser could still count on paper but was already becoming unsuitable for modern cruiser work. Surviving C-class ships were often converted into anti-aircraft cruisers with four-inch guns and radar because the navy no longer wanted them in the original cruiser role. Fiscal restraint and rules for retaining over-age ships therefore threatened to leave Britain with nominal strength that could not cover its patrol and trade-protection tasks.