pbA new history of the most crucial few months of the Arctic Convoys, when Germany's air power forced the Allies to retreat to the cover of winter.b p Between spring and autumn 1942, Germany was winning the battle of the Arctic Convoys. Half of PQ-15 was sunk in May, PQ-17 was virtually obliterated in July, and in September 30 percent of PQ-18 was sunk. The Allies were forced to suspend the convoys until December, when the long Arctic nights would shield them. pMark Lardas argues that in 1942, it was Luftwaffe air power that made the difference. With convoys sailing in endless daylight, German strike aircraft now equipped and trained for torpedo attacks, and bases in northern Norway available, the Luftwaffe could wreak havoc. Three-quarters of the losses of PQ-18 were due to air attacks. But in November, the Luftwaffe was redeployed south to challenge the Allied landings in North Africa, and the advantage was lost. Despite that, the Allies never again sailed an Arctic convoy in the sum