1 september1939
because they wanted to
England
England joined because Germany attacked Belgium
England joined WW1 on August 4th 1914.
joined in 1942
7 December 1941
The 8th of December 1941 was the date that the US joined world war 2
No
17th march 1914
There was no reluctance - cheering crowds and a rush of recruits everywhere. (You may be thinking of World War 2).
April 6 1917
No. Canada joined the war at the same time as England.