The entry of the USA into WWII in 1941 helped turn the tide in favor of the Allies in several key ways: 1) The US provided critical economic and material support to Britain and other Allied nations through measures like cash-and-carry and lend-lease programs, helping to reinvigorate their supplies and war efforts. 2) After direct entry into the war following the attack on Pearl Harbor, the US was able to rapidly produce vast military resources that overwhelmed the Axis powers. 3) US participation helped the Allies achieve control of the air and sea, restricting German U-boat operations and allowing for successful large-scale Allied campaigns like the D-Day invasion that ultimately led to victory.

1. Role of the USA

2. 1) Background
2) Indirect Involvement
3) Direct Involvement

3. Topic Inquiry Question:
“Was the entry of the USA in 1941
the main cause of Germany’s
defeat inWWII?”
Key words?

5.  Isolationist
sentiments were
strong in the USA –
Why?
▪ Effects of Great
Depression
▪ Horrors ofWorld War I
▪ Sense of Geographical
Isolation

6.  Neutrality Act
passed in 1937
▪ Based on this
cartoon, what
was the
purpose of the
NeutralityAct?

7.  Neutrality Act passed in 1937 – to
ensure that the USA wouldn’t
become involved in a foreign war
▪ Features included:
▪ The prohibition of American ships from
transporting passengers/materials to warring
nations
▪ The forbidding of US citizens from travelling
on ships to warring nations

9.  ‘Cash and Carry’ (Sep 1939)
▪ Allowed Britain and France to
buy arms from the USA on a
‘cash and carry’ basis
 Br/Fr could buy US-
produced weapons but had
to pay cash up front and had
to settle their own
transportation

10.  Lend-Lease Act (Mar 1941)
▪ Britain’s resources drained by 1940

12.  Lend-Lease Act (Mar 1941)
▪ Britain’s resources drained by 1940
▪ Under L-L Act, US could supply food,
weapons and equipment to Britain and other
countries whose defence was deemed vital
to US security
▪ Later extended to USSR in June 1941

13.  Lend-Lease Act (Mar 1941)
 Under L-LAct, payment for weapon
purchases could be deferred and payment
didn’t have to be in cash
 L-LAct gave theAllies a fresh injection of
supplies and resources needed to fight
Germany

14.  President Roosevelt (FDR) felt
that the USA should be the
‘arsenal of democracy’
 What does it mean?Take a guess!
 The idea that the USA should
actively support democratic
nations such as Britain in their
fight against theAxis powers

15.  USA increased aid to Britain after France fell to
Germany in 1940
 50 old destroyers given to the British in exchange
for 8 naval bases in the Caribbean

16.  Close bonds were forged between the USA
and Britain
 President Franklin D. Roosevelt (FDR) and
Churchill frequently corresponded with one
another
 In response, Germany and Italy joined Japan in the
Tripartite Pact in 1940 – committed to mutual
political, military and economic assistance

17.  FDR also planned to expand the US Army and
Navy and stepped up the process of
rearmament
Allies provided with psychological (moral)
and material support during a difficult period
 allowedAllies to gain military superiority

18. There are many among us who in the past closed their
eyes to events abroad-because they believed what
some of their fellow Americans told them—that what
was taking place in Europe was none of our business;
that no matter what happened over there, the United
States could always pursue its peaceful and unique
course in the world.

19.  There are many among us who closed their eyes, from lack
of interest or lack of knowledge; honestly and sincerely
thinking that the many hundreds of miles of salt water
made the American Hemisphere so remote that the people
of North and Central and South America could go on living
in the midst of their vast resources without reference to, or
danger from, other continents of the world …
 Today we are (now) more realistic. Let us be done with
both fears and illusions. On this evening, in our homes
in the midst of our American families, let us calmly
consider what we have done and what we must do.

20.  What was FDR’s message?
 FDR’s ‘fireside chats’ – convincedAmericans
to end isolationism

21.  Escort roles
▪ US navy escorted Allied convoys at sea after being
attacked by U-boats in late 1941
 Allied ships able to cross seas safely
Escort roles
oUS navy escorted Allied convoys at sea after being attacked by U-boats in late 1941
•Allied ships able to cross seas safely
Escort roles
oUS navy escorted Allied convoys at sea after being attacked by U-boats in late 1941
•Allied ships able to cross seas safely

22.  Economic sanctions on Axis Powers
▪ Resources like iron were restricted to deprive the Axis
Powers of resources needed for the war
▪ Japan’s US assets were also frozen when it invaded
Indochina in 1941
 Economic sanctions contributed to the
weakening of theAxis Powers as their
supplies were drained

24.  What prompted direct US entry into
WWII?
 http://www.youtube.com/watch?v
=bxIsVYdB0lA

25.  What prompted
direct US entry
into WWII?
 Japanese Attack
on Pearl Harbour,
7 Dec 1941
 ‘Day of Infamy’

26.  USA was the world’s largest industrial power
and it could produce military resources at a
rapid rate  Axis powers couldn’t keep up
 Factories converted to military production

27.  Also sent great numbers of US military
personnel to aid Allied military
campaigns

28. US participation helped
Allies achieve control of
the air and sea

29.  Control of air
 Allies able to destroy many German cities, military
sites and oilfields

30.  Impact?
▪ Slowed production of war materials
▪ Germany forced to focus on anti-aircraft guns
rather than tanks
▪ Luftwaffe lost control of the air

31.  Gaining naval supremacy
 Allies had important bases in the mid-
Atlantic

32.  Gaining naval supremacy
 Allies produced longer-range aircraft which
successfully attackedGerman U-boats and
planes
 http://www.youtube.com/watch?v=7zCBqpQwSeo
▪ Also produced better equipment like anti-
submarine weapons, radio communications and
radar
 Germany forced to recall U-boats in 1943 
Allied supremacy at sea

33.  Impact?
Air and sea control = tactical success
▪ E.g. D-Day landings made possible  Resulted
in Allied victory