> I guess the ostensible "national security" rationale (which clearly is not the only reason!) for this is that turbines severely degrade the utility of radar surveillance along the coastlines.
Could it be that they just feel that offshore wind infra is difficult to defend militarily?
No, they aren't any more difficult to defend than any other offshore platform. They do interfere with long-range land-based radar in a way that is problematic with the emergence of shipborne drones.
Order of magnitude increase in difficulty to defend a wind farm vs an oil rig. Wind farms are dispersed, not continuously manned, harder to monitor/enforce a 500m maritime safety zone of exclusion, have a greater attack surface (subsea cables, substations), and are easier to sabotage with plausible deniability
Could it be that they just feel that offshore wind infra is difficult to defend militarily?