A 2,017-ton German submarine appeared off the northern tip of Scotland during a recent military exercise, giving British commandos a launch point to reach shore by inflatable boat, scale cliffs, and direct the guns of a 401-foot Portuguese frigate at targets inland. The drill showed how allied forces carry out covert landings from submarines in difficult shoreline environments.

The exercise brought together several NATO partners, combining submarine operations with shore-based strike coordination in a high-pressure drill setting. Scenarios like this are growing in number as NATO focuses on amphibious and covert capabilities.

Separately, the Australian Naval Institute highlighted problems about vulnerable procurement networks underpinning nuclear submarine programs, a warning that creates new urgency to long-term procurement planning for Australia's future submarine fleet. Analysts say supply chain resilience will be essential as Australia works toward standing up its submarine capability.