I'm not familiar with the concrete law, but monopoly/market based rejections could probably be disputed and result in lengthy proceedings. Not so if you swing t

I'm not familiar with the concrete law, but monopoly/market based rejections could probably be disputed and result in lengthy proceedings. Not so if you swing the national security hammer. Also, as others have noted, it's quite possible that GHCQ has backdoors into ARM designs that would be jeopardized. But despite being owned by Softbank, Arm Ltd. is still incorporated in the UK and has their headquarters there. If chip design is seen as a essential national capability, the national security argument is valid regardless, in my opinion.