Nearly a decade ago, I traveled to Poland for the March of the Living, an event that brings the horrors of the Holocaust to life for thousands of children and adults from around the world. Over six days, my march toured the former sites of ghettos and gas chambers where the worst of humanity lay before us.

Six months earlier, I had completed Marine officer training, and I looked ahead toward a service obligation that I had committed to shortly after the terrorist attacks of 9/11.

I walked through these sites taken aback — a reasonable response, I believe — while looking at piles of human ashes, boxes of children’s shoes, and walls made from the headstones of Jewish gravesites.

Yet, I was confident in two ideas: the first, that America was without peer in its ability to prevent senseless death and destruction around the world, and I was lucky to be a part of that; and the second, that never in the United States would we allow the senseless and baseless targeting of a minority group to go unchecked, or worse, that such targeting would be driven by the President of the United States.

I’m still confident of the first idea, and although I no longer call myself a Marine full time, those of us that have are imprinted with the idea that wrongs must be righted by good people with the best intentions.

The second idea, however, may be slipping away.

On a day when the world mourned the senseless slaughter of millions of Jews, Gypsies, Poles and others, the President of the United States closed our borders, broke families apart, and condemned children to die at the hands of cluster bombs in warzones around the world.

America has broken faith with its permanent residents, turned its backs on interpreters from Iraq and elsewhere, and left young parents stranded in transit unsure if they can reach their final intended destination, children in tow, clutching their belongings in hopes of a brighter future.

The United States of America, once a shining beacon of hope and humanity for the world, has been draped in a dark blanket of fear.

We are a shell of ourselves, and I hardly recognize us.

Many people have asked me what one takes away from walking along the train tracks into Auschwitz, visiting Oskar Schindler’s factory, standing at a memorial site at Majdanek or crawling underground at the site of an uprising in the Warsaw ghetto.

What I learned is that societies reach their worst, incrementally.

The descent into intolerance is a slow descent, one marked by the incremental steps that divide us from them, perpetrators from victims, and the worthy from those that supposedly threaten to take it all away from us.

What at first appears to be a welcome change or a breath of fresh air may in fact be the spark that ignites repressed feelings of violence and rage. All of this will happen, incrementally.

What did we do to stop this?

In a few years we might wake up, like others in history before us, and discover that all we have to show for ourselves are regrets for our own inaction and monuments to our own mistakes.