That's because they were preparing for the biggest war in human history. This was the policy of militarism where building up a military was necessary to ensure that the people could fight against others. The number of soldiers in European armies increased twice in size in only 20 years between the 1890s and 1910s.
Aztecs were located in north america, particularly modern day mexico
I believe the most recent ice age ended nearly 11,700 years ago, but began nearly 2 million years ago.
Pretty sure it was the Soviet Union who claimed Ukraine, which is modern-day Russia i think.
American colonies eventually become independent creating the United States of America and establishing their own laws.
