Norfolk acknowledged this in 2018. You are right that they have been there much longer.

The City has been the home of the only North American headquarters for the North Atlantic NATO since 1953. The City and NATO desire to formalize the details of the donation and acceptance of the gift with a letter of acceptance. The donation of three entrance signs will be placed on existing City highway entrance locations at on Northampton Boulevard, E. Virginia Beach Boulevard and S. Military Highway.

https://www.norfolk.gov/DocumentCenter/View/36420/R-01-Approving-donation-from-the-North-Atlantic-Treaty-Organization?bidId=

General Milley is suggesting this is preparation to stop a potential big war.

https://www.defense.gov/Explore/News/Article/Article/2696189/milley-marks-full-operational-capability-of-nato-command-in-norfolk/