World War II holds a special place in the American psyche as the country's greatest triumph, and the U.S. military personnel of World War II are frequently referred to as "the Greatest Generation." Over 16 million served (about 11% of the population), and over 400,000 died during the war. The U.S. emerged as one of the two undisputed superpowers along with the Soviet Union, and unlike the Soviet Union, the U.S. homeland was virtually untouched by the ravages of war. During and following World War II, the United States and Britain developed an increasingly strong defense and intelligence relationship. Manifestations of this include extensive basing of U.S. forces in the UK, shared intelligence, shared military technology (e.g. nuclear technology), and shared procurement.
Both during and after the conclusion of  World War II, the United States formed a firm alliance with what country?
Britain