Hitler several times toyed with the idea of a descent upon the island and laid preliminary plans for it; but to forestall such a move British troops, soon joined by a Canadian force, had landed in Iceland on 10 May 1940.

In 1941, weakened by the withdrawal of some 50,000 troops in Greece and surprised by greatly reinforced German and Italian forces, Britain's Army of the Nile had been driven back, with serious losses, across the African deserts to the Egyptian border.

As the scope of Germany's aerial blitzkrieg widened, the people of Iceland grew more uneasy; for it to be "defended" by one of the belligerent powers, they felt, was an open invitation to attack by the other.

On 10 April 1941, while picking up survivors from a Dutch vessel torpedoed off the coast of Iceland, the U.S. destroyer USS Niblack (DD-424), which earlier in the month had been given the job of reconnoitering the waters about the island, went into action against a U-boat whose approach was taken as an intention to attack.

This was the first of a number of "incidents" that were to take place in the waters south of Iceland, where from this time forward the safety zone of the Western Hemisphere and Germany's blockade area overlapped.

On 13 April President Roosevelt received assurances from Prime Minister Churchill that Britain was determined to fight through to a decision in North Africa.

Discussions between General Chaney's staff and British officers had begun on 4 June on such matters as housing the American troops, the antiaircraft defense of Iceland, and the necessary fighter plane strength; and it was decided that a joint Admiralty, Air, and War Ministry committee would collaborate with the Special Observer Group in planning the relief of the British forces.

An agreement with the Government of Denmark was concluded on 7 July 1941 for the United States to relieve the British and Canadian forces on Iceland.

Guarded through coastal waters by vessels of the First and Third Naval Districts, the transports and accompanying freighters on the following day picked up their ocean escort and destroyer screen at a meeting point off the coast of Maine.

As outposts of defense, the North Atlantic bases were only imperceptibly affected by the entry of the United States into the war in December 1941.

The affirmation in the ARCADIA Conference (the Anglo-American conference in Washington, December 1941 – January 1942) of the strategy of concentrating an American air force in the United Kingdom acted as a catalyst on the hitherto uncertain and somewhat nebulous proposals that the United States take over the North Atlantic air route-the shortest path between America and the European front.

Furthermore, early plans and prior commitments and the desire of the British to transfer their garrison gave Iceland a special position in the tug of European strategy After the arrival of the December troop convoy a battalion of marines had taken over the positions of one of the British infantry battalions, which was immediately returned to the United Kingdom.

After 11 May only the British 146 Infantry Brigade, distributed among the three outports of Akureyri, Seydisfjordur, and Budareyri, and some Royal Air Force units remained.

The building of the Keflavik airfields, air ferrying activity, and troop transport operations over the sea lanes, and the fact that the United States had become one of the belligerents all meant that the size of the garrison had to be revised upward.

With the concurrence of the Air Forces, that the Army Engineers at once begin construction of an airfield in the vicinity of Keflavik suitable for heavy bombers and that the necessary funds be provided.

Completed before Meeks became operational, the first planes of the Eighth Air Force began coming through Patterson on their way to England, early in July 1942 when two of its three runways were in use.

At the peak of the Second World War, thousands of USAAF airmen were stationed at the airfields (Meeks and Patterson ) near Keflavik in temporary Quonset hut camps.

"The major problems concerned with aircraft ferrying had been largely solved," states the official history of the Air Transport Command.

The unit also conducted antisubmarine patrols in the North Atlantic and provided cover for convoys on the run to Murmansk, Soviet Union.

Up to this point the honors had gone to the Norwegian patrol squadron, which, under RAF command, was operating off the northern and eastern coast; but it was not long before the American air forces in Iceland had their chances at the Nazis.

On the morning of 14 August 1942 two American fighter pilots, Lt. E. E. Shahan and Lt. J. D. Shaffer, intercepted and destroyed a Focke-Wulf Fw 200 about ten miles north of Reykjavík.

Some of this air activity over the North Atlantic was undoubtedly related to the enemy's efforts to set up weather and radio stations in Greenland.

Another agreement signed between the United States and Iceland in 1946 permitted continued use of Keflavik Airport for flights in support of occupation forces in Europe.

During the past four decades, the Defense Force was "at the front" of the Cold War and was credited with playing a significant role in deterrence, and in 1951, the United States Air Force re-established a presence in Iceland, and the former Meeks Field, now known as Keflavik Airport, which became a NATO transport and interceptor base during the Cold War.