Britain commits £15 billion to sovereign nuclear warhead programme, with Astraea to replace Mk4A and retain Trident II D5 compatibility

The UK has committed £15 billion to develop the Astraea sovereign nuclear warhead, designed to replace the current Mk4A reentry body. The programme maintains compatibility with the Trident II D5 submarine-launched ballistic missile. Astraea represents a full modernisation of Britain's nuclear deterrent warhead for the Dreadnought-class SSBN. The investment underscores the UK's commitment to an independent nuclear capability through the mid-21st century.