Why a joint UK-Canada-Australia LHD is difficult

Could Britain, Canada, and Australia develop a common LHD?

Potentially, but their replacement schedules and priorities are misaligned, while crews, escorts, and Canada's submarine problem make a near-term common project unlikely.

Australia had only recently introduced its Canberra-class amphibious ships, so it was unlikely to seek a replacement soon. Another Australian hull would also need a crew and escorts. Canada was already struggling with submarine requirements, including the limitations of diesel submarines for Arctic operations. A common LHD remained possible, but the participating navies would have to reconcile different procurement priorities and support requirements.