When we think of D-Day, we tend to envision the waves of landing craft approaching the beaches and Landing Craft Tanks (LCTs) with barrage balloons in tow, or maybe waves of C-47s winging away from their bases in Southern England with their paratroopers. These are powerful visuals and while the soldiers and paratroopers really did do the heavy lifting of liberating France, these images overshadow a remarkable and invisible war that is often forgotten.