In 1943, he also directed two Allied propaganda films for the National Film Board of Canada, including Action Stations, about the Royal Canadian Navy's escorting of convoys in the Battle of the Atlantic.

The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada, the British Empire and the United States to the islands of Great Britain and ( during World War II ) to the Soviet Union and the Allied Countries in the Mediterranean.

Nevertheless with the introduction of escorted convoys shipping losses declined and in the end the German strategy failed to destroy sufficient Allied shipping.

In the Atlantic, escort carriers proved to be a vital part of Allied convoys, increasing the effective protection radius and helping to close the Mid-Atlantic gap.

At the time, most U. S. commanders at lower levels had little or no combat experience of any kind ; without the input of experienced British or Allied combat officers on the nature of modern warfare and enemy tactics, many of them resorted to formulaic training methods emphasizing static defense and orderly large-scale advances by motorized convoys over improved roads.

The concentration of the German fleet in Norway served three purposes ; namely as a threat to Anglo-American convoys carrying supplies around the North Cape to the Soviet Union, to deter an Allied invasion of Norway and as a fleet in being that tied down British warships at Scapa Flow that might otherwise be deployed in the Battle of the Atlantic.

Banjul served as an air stop for the U. S. Army Air Corps and a port of call for Allied naval convoys.

British convoys running through the western Indian Ocean were vital for supplying Allied forces in North Africa.

In addition, Allied warships attached to convoys were available:, and waited in the Kithira Channel and,,, and were nearby.

* SC convoys, a designation by Allied navies for a type of trans-Atlantic convoy during World War II

Moreover, the Germans had bases along the length of Norway, which meant, until escort carriers became available, Allied convoys had to be sailed through these areas without adequate defense against aircraft and submarine attack.

His mission was to prevent information about Allied convoys off the coast of Africa falling into enemy hands – he wrote later also of a suicide attempt at this time.

30, 000 merchant seamen were killed aboard convoy vessels during the war, but along with the Royal Navy, the convoys successfully imported enough supplies to allow an Allied victory.

This meant that the German air force would have additional airfields available to threaten Allied shipping and also to protect their own supply convoys and troops in Cyrenaica ; delaying Battleaxe could therefore mean facing stronger Axis opposition.

* August 10 – Reinforced by 250 Imperial Japanese Army aircraft from Rabaul, Japanese air forces in New Guinea are ordered to conduct an air offensive against Allied airfields on New Guinea and Allied convoys along the Papuan coast.

** German aircraft attack Allied convoys south of Sicily, sinking a tank landing craft and damaging other ships.

* December 2 – Adolf Hitler orders the Luftwaffes Fliegerkorps II to redeploy from the Soviet Union to Sicily and North Africa and together with Fliegerkorps X to form Luftflotte 2 under the command of Field Marshal Albert Kesselring, and orders Kesselring to achieve air superiority over southern Italy and North Africa, suppress Allied forces on Malta, ensure safe passage of Axis convoys to North Africa, paralyze Allied sea traffic in the Mediterranean, and prevent Allied supplies from arriving at Tobruk and Malta.

* June 14 – 16 – German and Italian aircraft join Italian surface warships and submarines in opposing Operation Harpoon, an Allied Malta resupply convoy from Gibraltar escorted by the British aircraft carriers and, and Operation Vigorous, a simultaneous resupply convoy from Alexandria, Egypt ; Royal Air Force and U. S. Army Air Forces aircraft from Malta and North Africa provide support to the convoys.

In the Atlantic, where German submarines again acted against Allied convoys, this part of the war was very reminiscent of the latter part of World War I.

* Convoy SC-7 for an account of one of the first Allied convoys to suffer a wolfpack attack

Teen Hunter Clubs were initially sponsored by affiliated members of the Allied Merchandising Corporation.

Nearly 3, 700 Allied ships were sunk at a cost of 783 German U-boats.

Research results obtained during that period were not shared between the Axis and the Allied powers during the war.

To isolate the Danube from any Allied intervention, Marshal Villeroi's 46, 000 troops were expected to pin the 70, 000 Dutch and English troops around Maastricht in the Low Countries, while General de Coigny protected Alsace against surprise with a further corps.

Whilst Allied preparations had progressed, the French were striving to maintain and re-supply Marshal Marsin.

A French reconnaissance under the Marquis de Silly went forward to probe the enemy, but were driven off by Allied troops who had deployed to cover the pioneers of the advancing army, labouring to bridge the numerous streams in the area and improve the passage leading westwards to Höchstädt.

Some Allied officers who were acquainted with the superior numbers of the enemy, and aware of their strong defensive position, ventured to remonstrate with Marlborough about the hazards of attacking ; but the Duke was resolute – " I know the danger, yet a battle is absolutely necessary, and I rely on the bravery and discipline of the troops, which will make amends for our disadvantages ".

At 02: 00 on 13 August, 40 squadrons were sent forward towards the enemy, followed at 03: 00, in eight columns, by the main Allied force pushing over the Kessel.

Many of the Allied generals were hesitant to attack such a relatively strong position.

" Marlborough, spotting this error, now countermanded Cutts ’ intention to launch a third attack, and ordered him simply to contain the enemy within Blenheim ; no more than 5, 000 Allied soldiers were able to pen in twice the number of French infantry and dragoons.

On the Allied right, Eugene's Prussian and Danish forces were desperately fighting the numerically superior forces of the Elector and Marsin.

If Holstein-Beck's Dutch column were destroyed, the Allied army would be split in two: Eugene's wing would be isolated from Marlborough's, passing the initiative to the Franco-Bavarian forces now engaged across the whole plain.

Tallard's squadrons, lacking infantry support, were tired and ragged but managed to push the Allied first line back to their infantry support.

These guns ( some of which were of the three barrelled kind first seen at Elixheim the previous year ) enjoyed good arcs of fire, able to fully cover the approaches of the plateau of Jandrenouille over which the Allied infantry would have to pass.

On Overkirk ’ s right flank, close to Ramillies, ten of his squadrons suddenly broke ranks and were scattered, riding headlong to the rear to recover their order, leaving the left flank of the Allied assault on Ramillies dangerously exposed.

Allied squadrons transferred from north to south gave the Allies a 5 – 3 advantage on the plain where some 25, 000 French and Allied cavalry were heavily engaged.

The final Allied reinforcements for the cavalry contest to the south were at last in position ; Marlborough ’ s superiority on the left could no longer be denied, and his fast-moving plan took hold of the battlefield.

Soon the Allied infantry could no longer keep up, but their cavalry were off the leash, heading through the gathering night for the crossings on the Dyle river.

Although early Reichswehr periodicals contained many translated works from Allied sources, they were rarely adopted.

While Allied Air Forces were tied to the support of the Army, the Luftwaffe deployed its resources in a more general, operational way.

The armoured and motorized forces were halted, by Hitler, outside the port city of Dunkirk, which was being used to evacuate the Allied forces.

Hermann Göring had promised the Luftwaffe would complete the destruction of the encircled armies, but aerial operations did not prevent the evacuation of the majority of Allied troops ( which the British named Operation Dynamo ); some 330, 000 French and British were saved.

Overall, Yellow succeeded beyond what most people had expected, despite the fact that the Allies had 4, 000 armoured vehicles and the Germans 2, 200, and the Allied tanks were often superior in armour and caliber of cannon.

After 1941 – 42, armoured formations were increasingly used as a mobile reserve against Allied breakthroughs.