Why was it easy for Great Britain and the US to become allies ?

Explanation:

In 1812, while Britain was focused on its war with France, the same country decided to take advantage of the situation and declare war on the United States. ... By WWI, the USA were supporting its English ally even over against the Germans, who arguably had populations that were almost as big.

answer: (fluidity)is the correct answer.

explanation: because of this characteristic, success on the battlefield depends in large part on the ability to adapt to proactively change events to our advantage as well as to react quickly to constantly changing conditions

in the 1950s, country music came into its own before rock-n-roll took off in the 60s while jazz and classical music continued to innovate