Seventy-five years ago, on December 7, 1941, the American Navy suffered the worst defeat in its history when a force led by six Japanese fleet carriers launched a surprise attack at the battleships at Pearl Harbor. Two of the eight battleships, Arizona and Oklahoma, were destroyed, and the other six were knocked out of action for many months. The Army Air Corps fields were attacked with great loss, and other smaller naval vessels were attacked as well.
The American carriers were at sea. Had those carriers been at Pearl Harbor, the whole course of the Pacific War would have been very different. During the first year of that conflict, only the carriers were able to slow down the Japanese advance. Battleships proved too vulnerable to air attack to fight major fleet actions alone. American submarines, which eventually would prove an incredibly potent force in the Pacific, were plagued by multiple problems with torpedoes which made them almost useless for many months.
The Japanese still might have inflicted crippling damage even with the carriers gone. The fuel depots for the American Fleet were at Pearl Harbor and so were major repair and maintenance facilities. Without these, the American Fleet could have had to operate out of San Diego, thousands of miles east.
The Japanese could also have utterly destroyed all the battleships, instead of just Arizona and Oklahoma, and these other battleships in two years were refitted and fighting the Japanese Navy. There were a number of other, smaller naval vessels at Pearl Harbor, which would be desperately needed in the first six months of 1942 and which follow-up attacks by the Japanese would have damaged or sunk.
Admiral Nagumo might have also done what Newt Gingrich played out in one of his brilliant counterfactual novels and ordered the two Japanese battleships with their 14-inch guns to pound every target those guns could reach while coyly holding the six Japanese fleet carriers back to pound on returning American carriers.
As America enters an increasingly dangerous world with our European allies threatened from within and our Pacific allies doubting our resolve, our incoming President Trump ought to grasp the dangers we face. (The superb team of capable military commanders he is surrounding himself with will surely help him with this task.)