What would need to change for HMAS Australia & HMS New Zealand to be retained under Washington?

Their orders would need to be delayed until they could be built as 15-inch-gun Tiger derivatives, their wartime service would need to demonstrate their value, and Washington would need a separate battlecruiser category with Dominion entitlements.

The 1909 Imperial Conference scheme paired a battlecruiser with cruisers, destroyers, and submarines for trade protection, convoy escort, deterrence, and raider hunting.

Canada repeatedly revisits its naval commitment and at one point considers three Queen Elizabeth-class battleships, while Australia and New Zealand place their orders quickly.

Governor-General Lord Dudley turns the 1909 conference concept into an unusually rapid Australian order and helps pull New Zealand into the scheme.

Dudley's partisan friction and fondness for vice-regal ceremony give Australian political leaders a plausible way to slow the 1909 order.

Lady Dudley's Australian nursing work receives brief attention, with uncertainty preserved about its original name and links to later health services.

The Indefatigables' 12-inch guns, limited survivability, older design, and damaged reputation leave Australia and New Zealand with little worth defending at Washington.

A slower Australian decision moves construction from the Indefatigable era to an enlarged Tiger design armed with 15-inch guns.

Three 15-inch-gun battlecruisers could enter service after Dogger Bank but before Jutland, reshaping the Grand Fleet's fast wing and wartime building choices.

Three large 15-inch-gun battlecruisers already under construction could weaken Fisher's case for cancelling battleships to free resources for Courageous, Glorious, and Furious.

Better results at Jutland, continued value at Dogger Bank, and a possible interception of von Spee by Japanese battlecruisers would strengthen the retention case.

Retention requires separate treaty categories for battleships, battlecruisers, and aircraft carriers, with fast capital ships justified by their trade-protection role.

Keeping modern battlecruisers could give Australia and New Zealand a visible security guarantee as the Anglo-Japanese Alliance ends.

Moving four Kongo-class ships into a separate battlecruiser allowance would release enough Japanese battleship tonnage for three improved Nagato-type ships.

Completing five Lexington-class battlecruisers would give the US Navy the fast scouting force it wanted, while leaving only one fast hull available for carrier conversion.

A proposed 28-knot minimum and 40,000-ton ceiling would let France consider dedicated designs and Italy classify fast Francesco Caracciolo-class ships as battlecruisers.

Because several signatories would begin below their allowances, the alternative Washington settlement could use timed construction slots in place of a simple building holiday.

Lexington battlecruisers may postpone American heavy cruisers, but Britain's global trade-protection and fleet-screening needs still drive County-class construction.

Pairing a Lexington battlecruiser with the surviving fast carrier could encourage a combined aviation-and-capital-ship doctrine before later Yorktown-class development.

In the proposed settlement, three 33,100-ton F3-like battlecruisers would use Britain's full 99,300-ton allowance.

The proposed treaty would leave Britain and the United States with eighteen battleships each, while their fast wings differ in ship size, numbers, and the place of Dominion forces.

Treaty permission to finish Francesco Caracciolo-class ships could give Italy a modern fast battle line and reduce the appeal of rebuilding older battleships.

French battlecruisers could form an overseas imperial-policing force, while the Netherlands might buy a foreign design, acquire an Italian hull, or build its own ship.

Although Japan would still accept an inferior ratio, permission to build new battleships could give the navy a concrete achievement around which to rally status and confidence.

Retained battlecruisers would give Australia and New Zealand a fleet cornerstone, with a difficult commitment to naval growth and supporting infrastructure.

A world crowded with battlecruisers could weaken the German commerce-raider strategy and redirect both German and Soviet capital-ship programmes.

A Dominion entitlement to one 27,000-ton carrier could support a large ship, while pairs of improved Hermes-sized ships depend on interpreting that one-ship restriction creatively.