The U.S. destroyers that might have reinforced Force Z

HMS Stronghold and four American destroyers of Destroyer Division 57 were intended reinforcements that did not join the historical sortie. Their arrival would have increased the screen from four destroyers to nine. That extra firepower might have saved Repulse, although probably not Prince of Wales. Admiral Thomas Hart's hesitation partly concerned the absence of organic air cover. With Indomitable present, Royal Navy carrier practice would also suggest an AA cruiser and another pair of destroyers. The combined possibilities produce an eleven-destroyer screen, although the American contribution remains a counterfactual assumption.