COVID-19 has sent Americans reeling. We’ve seen things we cannot ignore: the sufferings of our most vulnerable and the understated heroism of our frontline health-care workers. This weekend our country recognizes heroes of another kind: the men and women who gave their lives to protect our country. Memorial Day is not a “holiday” but a sacred day, particularly for those of us who loved or served with people who “gave the last full measure of devotion.” What’s the connection between the heartbreak and havoc of the past two months, and Memorial Day? The pandemic and its global chaos have shown...