The United States maintained neutrality up until the point where Japan bombed Pearl Harbor. After that, it was impossible for the US to keep to itself.
Explanation: The United States has long followed a policy of neutrality, even during the WWI was neutral until the sinking of a passenger ship with US tourists. America followed this policy between the two world wars, and the dispute they had with Japan were trying to resolve diplomatically. Us did not want to be involved in various disputes between states in Europe, but when the unexpected attack on the American port of Perl Harbour by Japanese aviation took place, America could no longer escape participation in WWII. The attack on Perl Harbour took place on December 7, 1941, after which the US officially entered the WWII announcing the war on Japan.
Based on the conditions above, the condition that the
soldier contract from fighting in trenches in the World War I is the trench
foot which is letter d. This is a medical condition in which soldiers from the World
War I suffered, this is where the feet has exposed in a prolong period time in
an unsanitary, cold and damp conditions that causes the surface of the tissue
to blacken and die.