A 2,017-ton German submarine appeared off the northern tip of Scotland during a recent military exercise, giving British commandos a staging platform to reach shore by inflatable boat, climb the coastline, and direct the guns of a 401-foot Portuguese frigate at targets inland. The drill illustrated how allied forces carry out covert landings from submarines in contested coastal terrain.

The exercise brought together a mix of allied military units, combining submarine operations with direct cliff assaults 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 consistent supplier availability will be critical as Australia works toward fielding nuclear-powered submarines.