No destroyers were received in exchange for the bases in Bermuda and Newfoundland. Both territories were vital to trans-Atlantic shipping, aviation, and to the Battle of the Atlantic. Although enemy attack on either was unlikely, it could not be discounted, and Britain had been forced to wastefully maintain defensive forces, including the Bermuda Garrison. The deal allowed Britain to hand much of the defence of Bermuda to the still-neutral US, freeing British forces for redeployment to more active theatres. It also enabled the development of strategic facilities at US expense which British forces would also use.