Question

Why did the allies agree to "Europe first"?

Answer 1

1/ It is WW II or World War II.
2/ The US agreed that with their immense resources the could wage was on both fronts but that the European front was more important than the Pacific, but did send troops to Australia and New Zealand for training.
3/ That fact is gratefully remembered here in New Zealand and Australia, as most of our troops were in the Middle East.