In a just world, there would be no need for Tuesday’s “March for Israel” in Washington.

Yet the past month has made clear many in the Western world are flirting with injustice and, worse, outright supporting evil.

We need to remind ourselves of what we as a civilization stand for — and, just as important, what we stand against.

The March for Israel will be in stark contrast with the countless protests that have swept college campuses and major American and European cities.

In those protests, supposedly educated people and elite voices have tried to justify Hamas’ barbaric Oct. 7 attack on Israel in which babies were beheaded and parents murdered in front of their children.

Students and citizens of free countries have loudly called for Israel’s obliteration, declaring that its attempts to defeat a terrorist enemy are acts of “oppression” and “colonialism.”

This is blatant antisemitism, but it’s also more: It’s an outright assault on the bedrock principles of Western civilization.

Those who criticize Israel are either willfully blind or easily misled.

They must not realize Israel protects the rights of its Jewish and Arab citizens alike, while Hamas denies freedom to all in Gaza.

They must not understand Israel respects human dignity, while Hamas sentences gays and lesbians to prison and even death.

And they don’t see Israel goes to great lengths to protect civilians, while the terrorists deliberately put innocent Palestinians in harm’s way, using them as human shields and abusing their deaths for propaganda.

It’s bad enough to hear statements of equivocation about Israel and Hamas.

It’s far worse to hear some Americans and Europeans say Israel is the enemy.

In a battle between good and evil, there is no room for such moral confusion.

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It inevitably has real-world consequences.

We’re already seeing assaults on Jews in America and Europe.

Vandals are targeting Jewish businesses and synagogues.

History shows where this road leads. When you encourage antisemitism, you end up with calamity.

And when you dehumanize one group of people, whether Jews or otherwise, you wind up encouraging atrocities against anyone.

For generations, when we in the West talked about the Holocaust, we boldly declared: “Never again.”

Now we must prove we meant it by helping Israel defeat those who would do it again.

America, Europe and every civilized nation must give Israel everything it needs to eliminate Hamas, which has promised to never rest in the slaughter of Jews.

There can be no cease-fire. Letting terrorists go guarantees they’ll perpetrate another Oct. 7 — or worse.

But victory on the battlefield is only part of the solution.

We must root out the moral cancer that has crept into our own society.

In its place, we must regain the strength that comes with clarity — specifically, we need clarity on the truth of our principles and the nature of the enemies who threaten us.

The future of Western civilization depends on us recognizing evil and confronting it with good.

This is why the United States must stand with Israel.

But Israel is not the only place in which civilization is challenged today.

In Iran, Russia and Communist China, we face an unholy alliance that gladly sacrifices innocent civilians for the sake of domination.

These regimes seek to destroy freedom and spread tyranny.

Their ultimate goal is to destroy America.

If we lack the courage to defend freedom or distinguish between good and evil, our enemies will win. First in their own backyard and eventually in ours.

We in the West face a great moral test. Whether we pass it will determine our civilization’s survival.

We can either unite once again around the timeless principles of human dignity and freedom or we can reject them in favor of passing fads and the pursuit of power, which paradoxically weakens us.

A look at college campuses suggests we are closer to making the wrong choice than at any point in the past century, yet there’s still time to remember who we are and what we stand for.

It will be on full display in Tuesday’s March for Israel.

For the United States, as the leader of the free world, must always stand for civilization over barbarism.

Nikki Haley is a Republican candidate for president. She was US ambassador to the United Nations and governor of South Carolina.