Prior to American entry into the Second World War, the governments of the United Kingdom and the US led by Prime Minister Winston Churchill and President Roosevelt came to an agreement exchanging a number of obsolete ex-US Naval destroyers for 99-year base rights in a number of British Empire West Indian territories.

The first aircraft to operate from the airfield were Blackburn Roc target tugs of 773 Fleet Requirements Unit, FAA, which had been formed at RNAS Bermuda on the 3 June 1940.

[2][3][4][5][6] The US Army was left as the only military establishment on the base after both RAF establishments (at Kindley Field and Darrell's Island) were withdrawn at the end of the war (followed by the closure of most of the Royal Naval Dockyard and withdrawal of the last regular British Army unit in the 1950s), although the RAF (and the Royal Navy Fleet Air Arm) has continued to use its end of the field, converted to a Civil Aviation Terminal by the Civil Aviation department of the Bermuda Government (headed by wartime RAF commander Wing Commander Mo Ware), as a staging post for trans-Atlantic flights.

The United States Army garrisoned Bermuda with ground forces for the remainder of the war, including Fort Bell.

Following the end of hostilities, its ground forces were withdrawn, other than those required for the defence of Fort Bell, on 1 January 1946, when US Army Air Transport Command took control of the entire base.

The airfield ceased to be distinguished within the base as the name Fort Bell was discontinued and Kindley Field came to be applied to the entire facility.

During the Cuban Missile Crisis, the base was also used to operate land-based U.S. Navy P-2 Neptune and P-3A Orion reconnaissance flights by aeroplanes tracking Soviet shipping in the Atlantic.

At the same time, the U.S. Navy was still operating anti-submarine air patrols with P5M/SP-5B Marlin seaplanes from NAS Bermuda at the West End.

These squadrons were frequently augmented by Naval Air Reserve P-3A or P-3B aircraft from various bases in the eastern United States, as well as NATO/Allied support consisting of Royal Air Force Hawker Siddeley Nimrod MR2s, Canadian Armed Forces CP-140 Auroras and other similar maritime patrol and reconnaissance aircraft from other NATO nations.