The men and women that fell in America's wars did not, usually, die protecting their homeland. They died for an idea.
The prime example is Memorial Day itself, the memorial of those that died on the battlefields of the Civil War. The question at issue, directly or indirectly, was the question of plantation slavery, a modern capitalist idea first developed by the republic of Venice and brought to hideous perfection in the sugar plantations of the West Indies and the cotton plantations of the Deep South.
So it has been ever since. The Spanish-American War was about colonialism; World War I was siding with Western European democracy against Central European authoritarianism. World War II was a battle against fascism--a secular religion that collapsed society into the national state. Then came the Cold War, the battle against communism--a secular religion that collapsed society into the national state. Now we are battling against the last holdouts against democratic capitalism, the Islamic extremists of the Middle East.
All those that fell in those wars all fell for the idea that we should blend political and economic power rather than allow one or the other to dominate.
Of course, the United States is not a paragon of virtue. It has not always pursued its vision to make the world safe for democratic capitalism with perfection. It has succumbed to the temptations of power; it has got into quarrels that it should have kept out of. But the U-turns of the Obama administration, on Iraq, on Guantanamo, on renewing the Patriot Act, have proved that US foreign policy is not just ginned up by right-wing cliques, but part of what America means.
The United States of America is a commercial democratic republic and it instinctively uses its power to nudge the world in the direction of democratic capitalism. It can't make everyone into democratic capitalists, but it can show how well it works, and it can make life difficult for thug dictators and thug activists throughout the world that raise a flag against the Pax Americana.
In the day-to-day slog of this work it often seems like nothing changes. And then you look around and notice that Germany is the leading democratic country in Europe, the Soviet Union doesn't exist. And you notice that India and China, those ancient civilizations that took 20th century detours into socialism and communism, are trying to make up for lost time in bringing the benefits of capitalist prosperity to their peoples.
Remember the Fallen. They did not die in vain.