Seventy years, that is how long it has been. The "Greatest Generation" is almost gone. Those still surviving are now in their nineties. It is a different nation because of the sacrifice they made.
The US entered the war a great power, it exited the war as one of only two superpowers. It entered the war with a small, decrepit military. It exited the war with the most modern and one of the largest militaries in the world. It entered the war making razor blades. It exited the war making nuclear weapons. It entered the war with a small middle class, and a weak economy. It exited the war in a boom economy lead by an ever expanding middle class.
Pear Harbor was the real beginning of that transition from potential greatness to manifest greatness. It is as clear a dividing line that history ever provides. There is pre Pearl Harbor US, and there is a post Pearl Harbor US.
That transition was accomplished by millions of citizens both famous and obscure. It was accomplished at Pearl Harbor starting on December 8, 1941. The US went from disaster to triumph in only four short years. The Axis powers never saw it coming. Only Yamamoto understood the tiger whose tail he was pulling. Only Yamamoto saw the inevitable end that the Empire of Japan was driving toward. But not even Yamamoto saw what Oppenheimer saw at Trinity. Fortunately for Yamamoto, he did not have to witness Shiva's dance on his homeland, he died before that awful event.
It is entirely appropriate that the bookends of the Pacific War are both set aside as places of memorial. The USS Arizona, and the impact sites of Hiroshima and Nagasaki are scared places; places of reflection. We need to remember these places. We need to remember what happened. We need to remember the shock, the horror, the pain and the death. We need to remember the sacrifice with humility.