Some regard today's holiday as little more than an excuse to give state employees a beach day off. But it in fact marks a momentous day in world history -- the end of War World II, a struggle that claimed the lives of an estimated 50 million people. Japan surrendered shortly after the United States dropped atomic bombs on two cities, Hiroshima and Nagasaki. The 70th anniversary of those bombings has reinvigorated a decades-long debate about whether America was right to do that. Critics of the action -- which killed an estimated 130,000 people, most of them civilians -- argue that the Japanese had sought negotiations in 1944, and that the United States thus had no moral right to fight on. Recognizing victory was no longer probable, Japanese leaders had hoped a negotiated peace might help them avoid being held accountable for their war crimes, to retain control of some of the countries they had conquered, and to keep their emperor in place. Indeed, some scholars now argue that the A-bombs were not even what drove the Japanese to surrender. Japan had hoped the Soviets might play a role in a negotiated end to the war. It was only after Russia invaded Japanese-held Manchuria, ending that dream, that the surrender came. We may never know exactly what led Japan to quit. We do know that there was no appetite in America for concessions to Japan, as victory neared against a country that had launched a sneak attack on the United States at Pearl Harbor; threatened our existence as a free society; treated civilians and prisoners with savagery; and forced enormous sacrifice on our people, as our young men struggled to push Japan back, island by island. It also seems highly probable that far fewer lives -- including those of Japanese civilians – were lost at Hiroshima and Nagasaki than would have been lost during an all-out invasion of Japan. We personally know Americans, stationed in the Pacific at the time, who were deeply grateful that President Harry S. Truman used the means at his disposal to end the war before the invasion commenced. Clearly, the surrender was beneficial to the world. With humane help from the United States, Japan avoided social collapse and starvation, and became a prosperous, innovative democracy, one of our strongest allies. That is what we celebrate today. Maybe, even on the beach, we can pause to remember those who defended our freedom and made very difficult decisions amid the chaos of war.