The intense level of military co-operation between the UK and US began with the creation of the Combined Chiefs of Staff in December 1941, a military command with authority over all US and British operations.
Kerjasama militer antara Britania dan Amerika dimulai dengan membentuk Kepala Staff Gabungan pada bulan Desember 1941, komando militer yang berwenang atas seluruh operasi militer Britania dan Amerika.