Un-restricted submarine warfare
The Second Great War aka World War 2
Vietnam.
Warmongers, dawg
1964-1975
No, it was a European war we chose to become involved in.
The US got involved in the war on: April 6, 1917.
The Korean War/conflict .
The Korean War ,
The sinking of the Lusitania caused the US to get involved.
The Cold War, then Vietnam.
Pearl Harbor attack
The German policy of unrestricted submarine warfare against shipping. This led to the sinking of the Lusitania in 1915. Great Britain and France were major trading partners.