Editing Lend-Lease (section)

===Cash and carry===
{{Main|Cash and carry (World War II)}}
In 1939, however—as Germany, Japan, and Italy pursued aggressive, militaristic policies—[[Franklin D. Roosevelt|President Roosevelt]] wanted more flexibility to help contain Axis aggression. He suggested amending the act to allow warring nations to purchase military goods, arms and munitions if they paid cash and bore the risks of transporting the goods on non-American ships, a policy that would favor Britain and France. Initially, this proposal failed, but after [[Invasion of Poland|Germany and the Soviet Union invaded Poland]] in September, Congress passed the [[Cash and carry (World War II)|Neutrality Act of 1939]] ending the munitions embargo on a "cash and carry" basis. The passage of the 1939 amendment to the previous Neutrality Acts marked the beginning of a congressional shift away from isolationism, making a first step toward interventionism.<ref name="NARA"/>

After the [[Battle of France|Fall of France]] during June 1940, the British Commonwealth and Empire were the only forces engaged in war against [[Nazi Germany|Germany]] and [[Kingdom of Italy|Italy]], until the [[Italian invasion of Greece]]. Britain had been paying for its materiel with gold as part of the "cash and carry" program, as required by the U.S. Neutrality Acts of the 1930s, but by 1941 it had liquidated a large part of its overseas holdings and its [[Gold reserves of the United Kingdom|gold reserves]] were becoming depleted in paying for materiel from the United States.<ref>{{harvnb|Allen|1955|pp=807–912}}</ref>

During this same period, the U.S. government began to mobilize for total war, instituting the first-ever peacetime [[Conscription|draft]] and a fivefold increase in the defense budget (from $2&nbsp;billion to $10&nbsp;billion).<ref>"17 Billion Budget Drafted; Defense Takes 10 Billions." ''The New York Times,'' December 28, 1940.</ref> The [[Two-Ocean Navy Act]] of July 1940 set in motion a rapid expansion of the [[United States Navy]]. In the meantime, Great Britain was running out of liquid currency and asked not to be forced to sell off British assets. Hampered by public opinion and the Neutrality Acts, which forbade arms sales on credit or the lending of money to belligerent nations, Roosevelt eventually came up with the idea of "lend–lease". As one Roosevelt biographer has characterized it: "If there was no practical alternative, there was certainly no moral one either. Britain and the Commonwealth were carrying the battle for all civilization, and the overwhelming majority of Americans, led in the late election by their president, wished to help them."<ref>{{harvnb|Black|2003|pp=603–605}}</ref> As the President himself put it, "There can be no reasoning with incendiary bombs."<ref name = 'NYT 30 12 1940'>"Address Is Spur To British Hopes; Confirmation of American Aid in Conflict is Viewed as Heartening, A joining of interests, Discarding of Peace Talks is Regarded as a Major Point in the Speech." ''The New York Times,'' December 30, 1940.</ref>

In September 1940, during the [[Battle of Britain]] the British government sent the [[Tizard Mission]] to the United States.<ref>{{cite news|last=Hind |first=Angela |url=http://news.bbc.co.uk/1/hi/sci/tech/6331897.stm | work=BBC News | title=Briefcase 'that changed the world' | date=February 5, 2007 | access-date=May 25, 2010}}</ref> The aim of the British Technical and Scientific Mission was to obtain the industrial resources to exploit the military potential of the [[research and development]] work completed by the UK up to the beginning of World {{nobr|War II}}, but that Britain itself could not exploit due to the immediate requirements of war-related production. The British shared technology included the [[cavity magnetron]] (key technology at the time for highly effective [[radar]]; the American historian James Phinney Baxter III later called "the most valuable cargo ever brought to our shores"),<ref>James Phinney Baxter III (Official Historian of the Office of Scientific Research and Development), ''Scientists Against Time'' (Boston: Little, Brown, and Co., 1946), p. 142.</ref><ref>{{cite news|title=Radar|url=http://www.newsweek.com/radar-169944|work=Newsweek|date= December 1, 1997}}</ref> the design for the [[Proximity fuze|VT fuze]], details of [[Frank Whittle]]'s [[jet engine]] and the [[Frisch–Peierls memorandum]] describing the feasibility of an atomic bomb.<ref>{{Citation |last=Brennen |first=James W. |title=The Proximity Fuze ''Whose Brainchild?'' |publisher=United States Naval Institute Proceedings |date=September 1968 |postscript=.}}</ref> Though these may be considered the most significant, many other items were also transported, including designs for [[rocket]]s, [[supercharger]]s, [[gyro gunsight|gyroscopic gunsights]], submarine detection devices, self-sealing fuel tanks and [[plastic explosive]]s.

On December 7, 1940, British Prime Minister [[Winston Churchill]] pressed Roosevelt in a {{nobr|15-page}} letter for American help.<ref group=nb>Churchill called the letter "one of the most important I ever wrote."</ref><ref>{{Cite web|url=http://www.fdrlibraryvirtualtour.org/graphics/07-06/7-5-Churchill-to-FDR_12-7-40.pdf|title=Letter, Winston Churchill to Franklin Roosevelt, December 7, 1940, pp. 14–15 – FDR Library}}</ref> In his December 29, 1940 [[Fireside Chat]] radio broadcast, President Roosevelt proclaimed the United States would be the "[[Arsenal of Democracy]]" and proposed selling munitions to Britain and Canada.<ref name = 'NYT 30 12 1940'/> Isolationists were strongly opposed, warning it would result in American involvement with what was considered by most Americans as an essentially European conflict. In time, opinion shifted as increasing numbers of Americans began to consider the advantage of funding the British war against Germany, while staying free of the hostilities themselves.<ref>Kimball 1969</ref> Propaganda showing the devastation of British cities during [[The Blitz]], as well as popular depictions of Germans as savage also rallied public opinion to the Allies, especially after [[Fall of France|Germany conquered France]].