Lend-Lease (sometimes called Lease-Lend) was a programme of financial and material aid given by the United States to its allies during the Second World War (1939 to 45). Food, weapons, ammunition, and agricultural equipment were amongst the goods which crossed the Atlantic and Pacific Oceans. The value of Lend-Lease goods has been estimated at around $50 billion. Payment was expected from the recipient states, although there was flexibility on how much, in what form, and when this was to be given. Lend-Lease was a massive operation, which ensured the US minimised its own military casualties while still using its tremendous economic power to drive the Allied cause. The programme became one of the great logistical achievements of the war effort, immeasurably helping the Allies win WWII.

At the outset of the Second World War, the United States, wary of becoming embroiled in a conflict on another continent, remained officially neutral and so could not directly intervene militarily. Giving material aid to participants in a war had been prohibited by the mid-1930s Neutrality Acts. Even loans were restricted by the Johnson Debt-Default Act, which excluded those nations that had not paid back the money lent during the First World War (1914 to 18). This was a heavy restriction because the only country which had paid off all of its debts to the US was Finland. President Franklin D. Roosevelt was determined to break down the traditional US foreign policy of isolationism any way he could within the law, and so he summoned Congress to repeal parts of the legislation blocking aid for the Allies. First, France and Britain were permitted to purchase arms (provided they paid cash and transported the arms themselves), and then another Congressional decision allowed US merchant ships to enter war zones and carry arms and ammunition as cargo. There was now a way to legally send much-needed assistance to Europe and elsewhere, yet for the United States to remain neutral.

Roosevelt, faced with direct appeals for aid from figures like British Prime Minister Winston Churchill, was even willing to bend the law a little. For example, the US President ensured British warships were repaired in US ports, and he sent warplanes to the USA's Canadian border, which allowed the Canadians to literally haul the planes into their own territory and then send them on to Europe. Another case involved an exchange of US destroyer warships for bases. Under this deal, the US promised to provide Britain with 50 destroyers (they received only 9 by the end of 1940), and in return, it acquired 99-year leases for several naval bases in the West Indies, Bermuda, Newfoundland, and British Guiana.

Roosevelt finally gained more freedom of action following the widespread outrage at the German U-boat attack on the US destroyer Kearny in October 1941 and the consequent repeal of many more restrictive neutrality laws. The US then went into full swing in its efforts to give aid to those defending freedom.

The Lend-Lease programme was designed, then, to give material and financial aid to those Allied nations which were fighting the three common enemies of the free world: Nazi Germany, Fascist Italy, and Imperial Japan. As the name suggests, the programme did not give goods for free; recipients were expected to repay the costs, but there was flexibility in terms of both the amount and timing of the repayments. Beneficiaries of the Lend-Lease programme included Great Britain, the USSR, China, South Africa, Egypt, Australia, and New Zealand. In total, over 38 countries received aid from the USA during the war.

As noted above, the US preferred cash for the goods sent via Lend-Lease. This soon became problematic since countries like Britain, not only suffering from the war but also from the consequent collapse in world trade, were running very low on cash reserves. With France's surrender in June 1940, Britain was left alone in Europe to face an aggressively rampant Germany and Italy. Britain could call on assistance from colonies like India and Australia, but the fact was that the size of the British Empire meant Britain was struggling both militarily and financially to protect its assets in South Asia, East Asia, Africa, the Middle East, and South America. On top of that, Adolf Hitler seemed determined to launch a German invasion of the British Isles.

Many in the US could not believe the government that presided over the vast British Empire was strapped for cash, but that was the reality, and Churchill even offered to show the nation's accounting books to Roosevelt to prove it. The British ambassador to the US starkly stated: "Britain's broke" (Dear, 531). There was a gradual realisation amongst many Americans that Britain was, in effect, fighting a war so that the US could remain on the sidelines militarily. An analogy came into common circulation of the moral and practical benefits of loaning one's fire hose to a neighbour when their house was on fire. If Britain collapsed under the pressure, then there would be nothing to stop the authoritarian aggressors of WWII from turning their sights on North America and setting houses ablaze there, too. On the other hand, giving aid carried risks. US material aid to Britain was regarded by the aggressor nations as no different from being fully involved in the war. It did seem that continuing and even increasing aid would eventually lead to the US becoming militarily embroiled in WWII.

Roosevelt did hold out hope that if enough aid were given, then US troops would not be needed in the conflict and US military casualties would be avoided. From December 1940, this attitude and that of the fire analogy meant Roosevelt was prepared to give material to the USA's democratic allies and not insist on particular conditions or exact figures of repayment. To continue the fire hose analogy, Roosevelt argued to Congress that if one's neighbour did manage to put out their fire but damaged the hose in the process, then compensation could be made not in terms of the precise cost of the hose but by an informal agreement that its value would be repaid in kind. A bill was passed by Congress in March 1941, and the US became the 'Arsenal of Democracy' as Roosevelt put it. Repayment terms were to be agreed according to what "the President deems satisfactory" (the wording of the legislation, quoted in Dear, 531), judging on a case-by-case basis. It should also be noted that many countries sent raw materials to the US, which were used to produce the manufactured goods they most needed.

Increasingly, as the war went on, payment was expected not in cash or goods but in concessions favourable to long-term US foreign policy and trade, such as opening up of closed markets and removing any restrictions previously applied to the US. There also remained some sticky issues, such as those who opposed giving aid to the communist USSR (which had become Adolf Hitler's principal enemy from the summer of 1941) and whether or not the US Navy should provide warships to defend the convoys carrying material aid to Europe and elsewhere.

The Lend-Lease materials sent by ship and air were very varied indeed, ranging from eggs to tanks. Although all payment for goods required the approval of Congress, the only restriction made by President Roosevelt on what could be included in the Lend-Lease programme was that the goods were needed "in the interest of national defence" (legislation text, quoted in Dear, 531). There were, otherwise, no legal restrictions on what could be sent to Allied nations. From August 1941, the general production and supervision of goods was the responsibility of a new organisation, the Office of Lend-Lease Administration (OLLA).

A major component was food for Britain, where people endured a strict system of rationing. Britain not only received US-produced food like cheese and meat but also agricultural equipment, which could improve homegrown production rates on British farms. Another major success was the delivery of tens of thousands of trucks to the USSR's Red Army, effectively making this a truly mobile force for the first time. US-built tanks helped boost the Allied cause in the North Africa Campaign. Small- and large-calibre munitions were vital to keep guns firing in all theatres of the war. Engines and spare parts ensured machines of war of all kinds could continue to operate.

The US industries providing Lend-Lease goods positively boomed. US war production was ramped up, and the huge logistical network required to transport the goods was quickly and efficiently developed. Most goods were delivered to Britain by merchant ships operating in convoys for greater safety. Goods not destined for Britain were then shipped on to places like Murmansk and the Persian Gulf. Lend-Lease production also had to face competition from the demands of the US military once the United States became fully involved in the war following the attack on Pearl Harbour in 1941. There was certainly a shortage of merchant ships in 1942, but production of these caught up with demand by 1943. Ultimately, Lend-Lease bases were established around the world from Australia to Chile to Morocco to China. Many such bases benefited from an expansion of local rail and road networks. Some aircraft were flown to their destination, often by civilian pilots, including women.

The Lend-Lease programme was hugely successful in getting material to where it was most needed. The total cost of goods sent can only be estimated because of the sheer scale of the project, but The Oxford Companion to World War II states, "between $42 and $50 billion of aid-food, military goods, oil, industrial production, and services went to America's wartime allies" (532). Britain received more than anyone else, around half of those goods, while the USSR received around one-fifth.

The Lend-Lease programme continued to split US politics as the war went on. A Senate decision to continue the programme in the spring of 1945 only won against those senators who wished to end it by a single vote. There were claims (sometimes true) that states were welcoming goods under Lend-Lease but then exporting them elsewhere for profit. Some in the United States called for a reduction of aid to Britain, the argument being that state was surely capable now of standing alone and was only using US aid to strengthen its own future position in the post-war world. This was not true since, having been forced to give up assets to the US, Britain was particularly affected by the long-term repercussions of Lend-Lease, as the historian S. Ambrose explains:

The Americans insisted that the British sell their overseas assets; this meant that at the end of the war the income that the British counted on and depended on for so long from her overseas investments was no longer there. They had been sold at American insistence…The Americans then moved into the areas that had previously been British colonies, whether simple or economic colonies. So Britain was in a much weaker position at the end of the war than she had been at the beginning and was not in a position to recover.

(Holmes, 129)

There had been (albeit vague) promises back in 1944 that Lend-Lease would continue after the war to help the much-needed and extremely costly task of rebuilding war-ravaged countries. Nevertheless, President Harry S. Truman, who took office in April 1945, immediately cancelled Lend-Lease following the Japanese surrender in August. Many governments felt let down by this decision, and Truman later admitted the programme should have continued for longer, although some states did receive substantial long-term loans, such as the $650 million lent to France in 1945. The question of repayments remained contentious. The USSR, for example, baulked at US demands to pay back an outstanding $2.6 billion. In fact, an agreement on the repayment terms was not reached until 1990.

Lend-Lease did leave a more meaningful legacy in the longer term. The United States and other nations came to regard aid-giving as a necessary and mutually beneficial branch of foreign policy, an attitude that continues to hold favour today with many governments around the world.