manoeuvre. Air–ground cooperation still required work, but the victories in
Tunisia and Sicily had given the Americans much-needed confidence in their
leadership, methods, and weapons, among which was the new Sherman tank.
On 3 September, the Allies crossed the Strait of Messina onto the Italian
mainland. The US 5th Army, under Lieutenant General Mark Clark, landed at
Salerno on 9 September, and was to drive towards Rome along the peninsula’s
west coast. Montgomery’s 8th Army landed at Reggio and Catanzaro, and was to
push northward to link up with Clark, then advance along the west coast. The
campaign’s scheme of manoeuvre thus consisted of two parallel drives up the
eastern and western coastlines of the peninsula. Amphibious ‘hooks’ would be
used to outflank any serious German resistance along with close air support and
naval gunfire. A fierce German counter-attack at Salerno, for instance, was
defeated, in part, by superior firepower in the form of naval gunfire and close
air support. The battle also illustrated how fire and movement were more than a
tactical technique: it was now also operational in nature, requiring planning and
coordination at corps headquarters and higher.
As a further example, the sites for the amphibious ‘hooks’ were, in part, limited
by the operational range of air cover, which was initially based in Sicily. As the
Allied advance progressed, its air cover would leapfrog forward to ensure cover-
age for the next series of operations. This task was, of course, made easier by the
fact that more of the Luftwaffe’s planes were being diverted to defend the German
homeland from Allied bombing offensives. However, the point is that the forward
movement of ground forces was often driven by the need to capture another
airfield so that air cover could be extended; thus, fire and movement, always
mutually reinforcing on a tactical level, had become mutually dependent on an
operational one.
The terrain on the Italian mainland favoured the defence, and the Germans
were able to establish four successive defensive lines across the peninsula, each of
which slowed the Allied advance considerably and inflicted heavy losses. Inclem-
ent weather and the eventual relocation of substantial Allied combat power for
the invasion of France also contributed. The Allies achieved a number of break-
throughs of these defensive lines, but no real breakout and exploitation. This
became a campaign of attrition, but it did tie down German forces that might
have been available for the Eastern Front, or used to strengthen defences along the
north-western and southern coastlines of France. However, the Allies paid a high
price, losing about 320,000 casualties (114,000 US) by the end of the war. 47
Mark Clark’s style contrasted sharply with Patton’s, so much so that the former
has been accused of incompetence. These accusations have some merit. The most
glaring example came after the fall of Monte Cassino and the penetration of the
Winter Line. Instead of attacking and cutting off the German 10th Army, he turned
his forces towards Rome, occupying it on 4 June 1944. Clark had disobeyed the
direct orders of his superior, General Harold Alexander, and enabled substantial
German forces to escape and establish a new defensive line north of Rome.
The invasion of Normandy on 6 June 1944 showed marked improvement in
the US operational art, with better cooperation among Allied air, sea, and ground
148 The Evolution of Operational Art