Regarded as an underhanded sneak attack outside the rules of civilized warfare, Pearl Harbor evaporated any reluctance of the American public to go to war. All of that changed after Japan's 7 December 1941 surprise attack on Pacific Fleet headquarters at Pearl Harbor, Hawaii. However, a mix of poor economic outlook, isolationist sentiments and post-World War I naval disarmament treaties reduced the effectiveness and preparedness of the USN for the Second World War. Over the years, the USN encountered various hurdles and successes in its conflicts with the British, French, and Spanish navies, evolving to be a major tool in American diplomacy with the Perry Expedition and President Theodore Roosevelt's 'big stick' foreign policy being notable examples. The United States inherited many of its nascent naval traditions from the British, from whom they won their independence in 1776. Early American ship-launched torpedoes do leave a great deal to be desired, but the real strength of USN ships lies in their ability to get into firefights and slug it out, relying on their superior guns and survivability to see them through. Most stock American ships are adequate for their roles, and while fully-upgraded ships perform better, they require little to no change in play style.

Ships fielded by the United States Navy (USN) sport great armor (albeit in an all-or-nothing design), main battery guns, and anti-aircraft (AA) capabilities, and are less hindered by stock configurations - many were built later and subsequently underwent fewer, less drastic upgrades (unlike Imperial Japanese Navy (IJN) vessels such as Kongo).

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